Open Collections

UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Thermal and photochemical reactions of Bridgehead halogen compounds Perkins, Robert Ralph 1976

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
831-UBC_1976_A1 P47.pdf [ 10.66MB ]
Metadata
JSON: 831-1.0061000.json
JSON-LD: 831-1.0061000-ld.json
RDF/XML (Pretty): 831-1.0061000-rdf.xml
RDF/JSON: 831-1.0061000-rdf.json
Turtle: 831-1.0061000-turtle.txt
N-Triples: 831-1.0061000-rdf-ntriples.txt
Original Record: 831-1.0061000-source.json
Full Text
831-1.0061000-fulltext.txt
Citation
831-1.0061000.ris

Full Text

THERMAL AND PHOTOCHEMICAL REACTIONS OF BRIDGEHEAD HALOGEN COMPOUNDS by ROBERT RALPH PERKINS B.Sc. (Hon.), Bishop's Un i v e r s i t y , 1972 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY i n the Department of CHEMISTRY We accept t h i s thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA A p r i l , 1976 In p r e s e n t i n g t h i s t h e s i s in p a r t i a l f u l f i l m e n t o f the requirements f o r an advanced degree at the U n i v e r s i t y of B r i t i s h Columbia , I agree that the L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e fo r reference and study. I f u r t h e r agree t h a t permiss ion for e x t e n s i v e copying of t h i s t h e s i s fo r s c h o l a r l y purposes may be granted by the Head of my Department or by h i s r e p r e s e n t a t i v e s . It i s understood that copy ing or p u b l i c a t i o n of t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l not be a l lowed without my w r i t ten pe rm i ss i o n . Department of O^-e 0 , ^ ^ . ^ The U n i v e r s i t y of B r i t i s h Columbia 2075 Wesbrook Place Vancouver, Canada V6T 1WS - i i -ABSTRACT Supervisor: Dr. R.E. Pincock A method of halogen exchange at normally unreactive bridgehead p o s i t i o n s was developed u t i l i z i n g the i n s i t u generation of aluminum t r i h a l i d e s from aluminum f o i l and i o d i n e , l i q u i d bromine and gaseous c h l o r i n e i n various solvents. The r e s u l t i n g solutions of aluminum iod i d e , bromide and ch l o r i d e promoted rapid exchange of primary, secondary and t e r t i a r y halides under mild conditions and i n high y i e l d . Aromatic halides proved to be i n e r t to the re a c t i o n conditions. Halogen exchange was shown to proceed from C I — ^ Br - ) I as w e l l as I — 7 Br—>C1. The rate of the r e a c t i o n was found to follow the r e l a t i v e s t a b i l i t y of the corresponding bridgehead carbenium ions i . e . 3 7 l-tricyclo£3.3.1.1 ' 3decyl(adamantyl) "7 l-bicyclo{2.2.23octyl 7 1-bicyclo-0.2.1]heptyly7 9-triptycenyl(9,10-0-Benzenoanthracene-9,10-dihydro). Photochemical reactions of bridgehead h a l i d e s of the adamantyl and bicyclo[2.2.lJheptyl systems were examined and found to follow both free r a d i c a l and i o n i c pathways, the r e l a t i v e amount of each depending upon the halogen atom and the solvent used. Iodides reacted v i a an almost exclusive i o n i c pathway, ch l o r i d e s v i a an exclusive free r a d i c a l pathway and bromides v i a both pathways. With polyhalogen compounds the l o s s of halogen atoms was stepwise, no evidence f o r any "dehydro" or "propellane" type intermediates r e s u l t i n g from concerted los s of two halogens was found. The i r r a d i a t i o n of bridgehead iodides i n alcohols produced bridgehead ethers with bridgehead amides r e s u l t i n g from re a c t i o n i n a l k y l n i t r i l e s . Reaction i n a l k y l amines did not lead to bridgehead amines and reduction products were formed instead. Halogen exchange was observed for the i r r a d i a t i o n of adamantyl iodides i n halogenated solvents while for adamantyl bromides, chlorides and f l u o r i d e s halogenation was found. - i i i -The nuclear magnetic resonance spectra ( XH, X J C and 1 7 F ) of the 3 7 halogenated bridgehead d e r i v a t i v e s of tricyclo£3.3.1.1 'Jdecane (adamantane) showed anomalous chemical s h i f t s upon successive ad d i t i o n of halogen atoms possibly due to i n t e r a c t i o n of the back lobes of the adamantane bridgehead carbon atoms. - iv -TABLE OF CONTENTS Page INTRODUCTION 1 A. General 1 B. Ionic Halogenation 5 C. Free Radical Halogenation 17 D. Photochemistry of Alkyl Halides 23 E. Objectives of Present Research 26 RESULTS 27 A. Halogen Exchange 27 B. Photochemistry of Halides 31 DISCUSSION 37 A. Halogen Exchange 37 B. Photochemistry of Bridgehead Halides 60 1. In Alcohol Solvents 61 2. In Alkyl N i t r i l e Solvents 76 3. In Amine Solvents 79 4. In Halogenated Solvents 81 C. Discussion of Spectral Results 86 1. Mass Spectra 86 2. Infrared Spectra 89 3. Nuclear Magnetic Resonance 91 a) Proton (7H) 91 b) Carbon ( Cl 105 c) Fluorine ( F) 124 CONCLUSIONS AND SUGGESTIONS FOR FURTHER STUDY 129 EXPERIMENTAL 131 A. General 131 B. B romoadaman t anes 134 C. Fluoroadamantanes 141 D. Chloroadamantanes 147 E. Iodoadamantanes 152 F. Triptycenes 159 G. Adamantyl Bridge Halides 162 H. 4-t>-Butylcyclohexyl halides 176 I. Alkoxyadamantanes 186 J. Adamantyl Amides 207 K. Mixed Adamantyl Halides 215 BIBLIOGRAPHY 230 APPENDIX 239 - V -FIGURES Figure # Page I Relationship of S t r a i n Energy versus Angle Size i n 50 1-Adamantyl Cation I I U l t r a v i o l e t Spectra of Bridgehead Adamantyl Iodides 70 I I I Jablonski Diagram f or Excited States 70 IV U l t r a v i o l e t Spectra of Anthracene and 9,10-Dibromo- 72 anthracene V E f f e c t of E t h y l Iodide on the U.V. Spectrum of 72 1-Chloronaphthalene VI Free Radical Halogenation of Adamantarte 83 VII I nfrared Spectra of 3,3'-Dihalo-l,l'-Biadamantanes 89 VIII I n f r a r e d Spectra of Syn 1,4-Dihaloadamantanes 90 IX Proton NMR Spectrum of 1-Bromoadaraantane 91 X Proton NMR Spectra of 1-Methoxyadamantane 92 XI Proton NMR Spectrum of 1,3,5-Triiodoadamantane 95 XII Observed Chemical S h i f t of the £2 Protons versus Number 97 of Halogen Atoms XIII Observed Chemical S h i f t of the p ' Protons versus Number 98 of Halogen Atoms XIV Observed Chemical S h i f t of the Protons versus Number 100 of Halogen Atoms XV Proton NMR Spectrum of 2-Bromoadamantane 103 XVI Proton NMR Spectra of syn-1,4-dihaloadamantanes 104 XVII Carbon NMR Spectrum of 1-Bromoadamantane 106 XVIII Chemical S h i f t ofjg and p' Carbons versus Numbers of 110 Halogen Atoms XIX Chemical S h i f t of <X. Carbons versus Number of Halogen 111 Atoms XX Chemical S h i f t of o" Carbons versus Number of Halogen 115 Atoms - v i -TABLES TABLE \\ PAGE I Free Radical Halogenation of Adamantane 19 II S t r a i n Energy of Isomeric Biadamantanes 47 I I I S t r a i n Energy of B i c y c l i c Systems 54 IV E f f e c t of Added Azide on the Rate of S o l v o l y s i s 57 V U l t r a v i o l e t Spectra of Adamantyl Halides 61 VI T r i p l e t L i f e t i m e and the Rate of Intersystem Crossing 73 VII T r i p l e t Energies for Various S e n s i t i z e r s 75 VIII Energy Conversion Table 75 IX Average Carbon-Halogen Bond Strength 75 X Fragmentation Pattern of Adamantyl Amides 87 XI Fragmentation Pattern of Norbornyl Amides 88 XII Fragmentation Pattern of 1-Alkoxyadamantanes 88 XIII Fragmentation Pattern of 1,3-Dialkoxyadamantanes 89 XIV Proton and Substituent S h i f t s of 1-Haloadamantanes 93 XV Experimental and Calculated Proton Chemical S h i f t s of 94 1,3-Dihaloadairiantar.es XVI Experimental and Calculated Proton Chemical S h i f t s of 95 1,3,5-Trihaloadamantanes XVII Experimental and Calculated Proton Chemical S h i f t s of 96 1,3,5,7-Tetrahaloadamantanes XVIII Benzene Solvent S h i f t s f o r 1,3,5-Trihaloadamantanes 99 XIX Experimental and Calculated Proton Chemical S h i f t s of 101 l-Chloro-3-Haloadamantanes XX Experimental and Calculated Proton Chemical S h i f t s of 102 ^1,3-Dihalo-5-Haloadamantanes XXI C Chemical S h i f t s of 1-Monohaloadamantanes 107 XXII Experimental and Calculated Carbon Chemical S h i f t s of 108 1,3-Dihaloadamantanes XXIII Experimental and Calculated Carbon Chemical S h i f t s of 108 1,3,5-Trihaloadamantanes XXIV Experimental and Calculated Carbon Chemical S h i f t s of 109 1,3,5,7-Tetrahaloadamantanes XXV Average Deviation of Observed from Calculated Chemical S h i f t s 109 f o r D i , T r i and Tetrahalides XXVI Chemical S h i f t of Various Halogenated Methanes 112 XXVII Carbon Chemical S h i f t s of l,4-DihalobicycloJ_2.2.fjhaptane 113 and octane XXVIII Carbon and Substituent S h i f t s of Dihalides 114 XXIX Experimental and Calculated Carbon Chemical S h i f t s of 116 l-Halo-3-H^loadamantanes XXX Experimental and Calculated Carbon Chemical S h i f t s of 117 1,3-Dimethyl-5-Haloadamantanes XXXI Experimental and Calculated Carbon Chemical S h i f t s of 118 1,3-Dimethyl-5,7-DihaloadamantaneS XXXII Experimental and Calculated Carbon Chemical S h i f t s of 118 3,3'-Diahlo-1,1'-Biadamantanes - v i i -TABLE # PAGE 13 XXXIII C Chemical S h i f t s of 1-Alkoxyadamantanes 120 XXXIV Experimental and Calculated Carbon Chemical S h i f t s f o r 121 1,3-Dialkoxyadamantanes XXXV Experimental and Calculated Carbon Chemical S h i f t s of 122 Unsymmetrical Disubstituted Adamantanes XXXVI Deviation from A d d i t i v i t y f o r Bridgehead Carbons of 123 ^-Substituted Adamantyl Halides XXXVII F Chemical S h i f t s of Substituted 1-Fluoroadamantanes 125 XXXVIII Fluorine and Substituent Chemical S h i f t s of A l k y l 127 Substituted 1-Fluoroadamantanes XXXIX A c i d i t i e s of Substituted 1-Adamantane Carboxylic Acids 127 XL S o l v o l y s i s of 4-Substituted l-Bicyclo£2.2.2} o c t y l 128 Brosylates - v i i i -ACKNOWLEDGEMENTS I would l i k e to express my sincere gratitude to Dr. R.E. Pincock fo r h i s continual support and many hours of h e l p f u l discussions during the course of t h i s work. I also wish to thank Dr. J . Haywood-Farmer f o r h i s encouragement and support during my f i n a l year as an undergraduate which enabled me to make i t to U.B.C. Ad d i t i o n a l thanks go to Dr. B. Jennings f o r suggestions concerning the photochemical work , and to Dr. Fu-Ning Fung f o r h i s a i d i n proof-reading the f i n a l copy of t h i s t h e s i s . A deep sense of gratitude i s direc t e d towards my wife C l a r i c e , who spent many long hours typing t h i s thesis i n s p i t e of the d i s t r a c t i o n s caused by our two month old daughter J e s s i c a . This t h e s i s i s dedicated to them with love. A f i n a l word of thanks goes to Mr. B. Lee who managed to keep h i s sanity despite the scores of samples I submitted to him during my stay. - ix -Dream C r y s t a l B a l l B l i n d Guess S l i d e Rule Hope Fear and j u s t a touch of F a i t h Hal Clement - 1 -. INTRODUCTION The s p e c i a l character of reactions at the bridgehead p o s i t i o n s of p o l y c y c l i c systems was f i r s t noticed by Bartlett''" i n 1939. His proposal that these systems would be an i d e a l area to study r e a c t i o n mechanisms and the preferred geometry of t r a n s i t i o n states has been proven over-whelmingly correct again and again over the past 36 years by many research 2 groups around the world. The f i r s t example discovered involved the r e l a t i v e inertness of the 1-apocamphyl system. A - M / ^ v _ ) CI A g N Q 3 NO REACTION KOH O H PCi5_ _) NO REACTION At the time t h i s work was published i t was generally accepted that the only way i n which one anion could replace another i n any n e u t r a l mole-.ule was v i a a Walden in v e r s i o n (today known as the S^2 displacement r e a c t i o n ) . B a r t l e t t reasoned that i n the apocamphyl system (as well as other r i g i d p o l y c y c l i c molecules) t h i s type of displacement was impossible and that the observed inertness would be a r e s u l t of the inherent i n s t a b i l i t y of - 2 -the carbenium ion n e c e s s a r i l y produced by a unimolecular r e a c t i o n . This concept was l a t e r r e f i n e d to suggest that carbenium ions would prefer a 2 sp planar geometry allowing the three bonding o r b i t a l s to be as f a r apart as p o s s i b l e . The vacant p o r b i t a l would be at r i g h t angles to the plane of the bonding o r b i t a l . This planar arrangement has been supported by 3 4 5 t h e o r e t i c a l c a l c u l a t i o n s as well as by nmr and i n f r a - r e d studies of several carbenium ion s a l t s . Thus i n systems where the molecular geometry p r o h i b i t s p l a n a r i t y a bridgehead carbenium ion rea c t i o n w i l l be slower than f o r a system i n 2d which a planar intermediate could r e a d i l y be formed . Therefore an examination of the rate of s o l v o l y s i s f o r a se r i e s of bridgehead compounds would lead to a r e l a t i v e order of carbenium ion s t a b i l i t i e s as shown below : (the rates have been corrected f o r diff e r e n c e s i n the leaving group) - 3 -T i l l s m e t h o d o f u s i n g r e l a t i v e r a t e s i s v a l i d o n l y i f t h e t r a n s i t i o n s t a t e s f o r t h e r e a c t i o n s a l l f a l l a t t h e s a m e p o i n t a l o n g t h e r e a c t i o n c o o r d i n a t e . T h e a s s u m p t i o n o f e q u a l d e g r e e o f i o n i z a t i o n h a s b e e n m a d e p r e v i o u s l y s o t h a t r e l a t i v e r a t e s f o r a . s e r i e s o f c l o s e l y r e l a t e d c o m p o u n d s (ej>. b r i d g e h e a d b r o m i d e s ) m a y b e t a k e n t o f a i r l y w e l l r e p r e s e n t s t a b i l i t y ' ' . T h e l a r g e r t h e . s i z e o f t h e r i n g s c o m p o s i n g t h e b r i d g e d s y s t e m t h e m o r e 2 r e a d i l y w i l l a n s p h y b r i d i z e d c a r b o n b e a c c e p t e d a t t h e b r i d g e h e a d . T h e r e f o r e a c o n t i n u e d i n c r e a s e i n t h e r i n g s i z e s h o u l d l e a d t o r a t e e n h a n c e m e n t f o r b r i d g e h e a d s o l v o l y s i s r e l a t i v e t o t - b u t y l h a l i d e . Two s u c h g e x a m p l e s a r e k n o w n a n d a r e s h o w n b e l o w : -X K rcl X=Ci 1.0 10 10 E m p i r i c a l f o r c e , f i e l d c a l c u l a t i o n s o n b i c y c l o [ 3 . 3 . 3 J u n d e c a n c ( m a n x a n e ) i n d i c a t e t h a t a t o t a l o f 6.8 k c a l o f s t r a i n e n e r g y w o u l d b e r e l i e v e d i n g o i n g g f r o m t h e p a r e n t h y d r o c a r b o n t o t h e b r i d g e h e a d c a r b e n i u m i o n . T h i s i s a 3 r e s u l t o f t h e a n g l e s t r a i n i n t h e m o l e c u l e ( n o r m a l s p h y b r i d i z e d c a r b o n a t o m s h a v e a n g l e s o f 109.5° w h i l e i n m a n x a n e . c a l c u l a t i o n s s h o w ^-C^C^Cg = 115.2°, Z.C1C2C3 - 118.8° a n d ^-C?C3C4 = 118.2°). T h i s e x t r e m e r e a c t i v i t y i s i n d i c a t e d b y t h e f a c t t h a t a p e n t a n e s o l u t i o n o f m a n x a n e i s s p o n t a n e o u s l y c o n v e r t e d t o t h e m o n o p e r o x i d e ( X = OOH) b y p a s s i n g a s t r e a m o f a i r t h r o u g h i t . T h e c h l o r i d e s o l v o l y z c s 10 t i m e s a s f a s t a s j j - b u t y l c h l o r i d e , a n d i s t o t a l l y c o n v e r t e d t o t h e a l c o h o l ( X = OH) u p o n e x p o s u r e t o a t m o s p h e r i c m o i s t u r e f o r a f e w m i n u t e s . F u r t h e r c a l c u l a t i o n s A -i n d i c a t e that the presently unknown 1-chlorobicyclo J A . A . 4 J tetradecane 8 w i l l be even more r e a c t i v e , s o l v o l y z i n g approximately 10^ times as f a s t as _t-butyl c h l o r i d e . The above bridgehead compounds solvolyze over a range of 20 orders of magnitude. As a r e s u l t of extreme n o n r e a c t i v i t y the synthesis of bridgehead d e r i v a t i v e s of the smaller r i n g systems has been d i f f i c u l t , . o f t e n r equiring long and roundabout routes. The bridgehead halogen compounds are the most use f u l intermediates. Some of the synthetic routes which have been employed to obtain them are shown below: + C H ? CH 2 -±=±) ^Cl H 9 Pd/n E t 3 N r e f 9 X=Br,l - 5 -Bridgehead Ionic Substitution Because of the greater r e a c t i v i t y i n the larger ring systems, direct ••• -Vo's "u." b<» used to obtain bridgehead halogen compounds. The most useful technique has been direct bromination. ref 13 95% r<?f 1 7 In a l l cases exclusive bridgehead brominatirn occurs because of the greater s t a b i l i t y of the bridgehead carbenium ion over any of the secondary cations. Once is o l a t e d , the above bromides have been converted to the other bridgehead halogen compounds d i r e c t l y with concentrated acids or via. the corresponding 1-hydroxy compounds. The reactions are exemplified f o r 1-bromoadamantane. r e f 1 9 21 Peterson has also found that bromine may replace other substituents as shown below: X=F,CI,OH 8 0 - 9 0 % As a r e s u l t of the e l e c t r o n withdrawing nature of bromine, a d d i t i o n a l 2 2 halogenation requires more vigorous conditions with added Lewis acid c a t a l y s t s . The same i s true f o r a l k y l substituted adamantanes as w e l l . However, McKervey and co-workers have r e c e n t l y discovered that s p e c i f i c diamantane d i o l s may be p r o d u c e d 1 6 5 by use of the fungus Rhizopus Nigricans as shown: 7 5 % As a consequence of symmetry the other diamonoid hydrocarbon systems y i e l d highly complex mixtures of products from Lewis a c i d brominations ( i f they do not also rearrange to substituted adamantanes under the r e a c t i o n c o n d i t i o n s ) . 23 Olah has recently published a f a c i l e method of producing bridgehead and bridge h a l i d e s from the corresponding alcohols with a l k a l i h alides i n polyhydrogen f l u o r i d e - p y r i d i n e s o l u t i o n . 24 St e t t e r has found that the adamantane r i n g may be chlorinated d i r e c t l y i n CCl^ with aluminum chl o r i d e to y i e l d a mixture of the monochloride and d i c h l o r i d e i n 85% y i e l d . Use of t h i o n y l c h l o r i d e i n place of CCl^ led to the formation of the t r i c h l o r i d e . K :i . -+-A1CL 15 85 75! SOC). 56% The only other d i r e c t method of synthesizing bridghead h a l i d e s was 25 found by Inamoto . Hydride a b s t r a c t i o n from 1-substituted adamantanes by _t_-butyl cation i n the presence of hydrogen halides y i e l d e d the corresponding bridgehead halogen compound. HX/r-USO/t ^ t -BijOH x x=ci,Br Y = H ; C H 3 C H 2 C | 70-90% Bridgehead halides may also be produced by use of precursors to the diamonoid molecules. Rearrangement of exo or endo-tetramethylenenorbornane and exo or endo-trimethvlenenorbomane i n the presence of aluminum chl o r i d e led to the formation of chlorinated adamantanes. S i m i l a r l y , rearrangement 27 of a hydrogenated norbornadiene dimer i n the presence of chlorosulphonic acid l e d to the production of 4,9-dichlorodiamantane. 26 - 10 -74% AICI 3  CH3COCI 8 2 % Hp/Pt } C 1 4 H 2 0 CISO3H ) -45° CI 8 2 % An Indirect method of synthesizing halogenated adamantanes has been e l e c t r o p h i l i c additions to dehydroadamantanes. Work performed i n t h i s laboratory has shown that 1,3-dehydroadamantanes are formed from the rea c t i o n of 1,3-dihaloadamantanes with e i t h e r sodium at room temperature or n-butyl l i t h i u m at -35° C i n d i e t h y l ether with added has been observed f o r 2,4-dehydroadamantane. Once i s o l a t e d , both dehydro-adamantanes may be used to synthesize substituted adamantanes. 28 Secondary halides have been i s o l a t e d i n low y i e l d s from the hydrogen 29 ha l i d e addition to 2,4-dehydroadamantane HMPA 30 These highly r e a c t i v e , oxygen s e n s i t i v e dehydroadamantanes may be e a s i l y i s o l a t e d by sublimation under nitrogen. The same ease of p u r i f i c a t i o n - 11 -0° X + H m a j o r Better y i e l d s have been r e a l i z e d from additions to 1,3-dehydro-adamantane^^'^'''. h As can be seen from the above examples the synthesis of t e r t i a r y or secondary adamantyl halides i s r e l a t i v e l y straightforward; however, the i s o l a t i o n of mixed bridgehead and bridge halides requires a d d i t i o n a l manipulations. Syn and a r t t i - l , 4 - d i h a l i d e s may be i s o l a t e d from the Lewis acid catalyzed rearrangement of gem-adamantyl d i h a l i d e s as shown below. The reactions are not clean however; the 1,4-dihalides must be separated from the other reaction products. - 12 AJCJ-ref 32 ref 33 34 The i s o l a t i o n of 1,2-adamantyl d i h a l i d e s f i r s t requires the synthesis of t r i c y c l o [4.3.I.O. 3' 8] decan-4-one (protoadamantanone) v i a the following route 35 Upon treatment with PC1.-/PC1.J t h i s ketone y i e l d s two products; the 36 desired 1,2-dichloroadamantane and 4-chloroprotoadamantene (which may be converted to the d i c h l o r i d e with b o i l i n g HC1). Treatment with PBr^/PBr^ leads d i r e c t l y to 1,2-dibromoadamantane. P X 3 X = B r ^ \ 297. - 13 -Related to t h i s , the 1 , 2-diiodide requires an extra synthetic step, production of the hydrazone 3 7. ) 0° As can be seen from the above examples there are many ways of preparing halogenated adamantanes and other p o l y c y c l i c hydrocarbons, but there have been few attempts made to convert one h a l i d e to another. Methods of halogen exchange i n a c y c l i c systems have been known f o r 38 many years but most f a i l to work o n . t e r t i a r y centers. One of the e a r l i e s t 3 9 i s the F i n k e l s t e i n r e a c t i o n f o r converting primary c h l o r i d e s and bromides to the corresponding iodides using Nal i n acetone or a higher molecular vreight ketone. The re a c t i o n proceeds because NaCl and NaBr are insol u b l e i n the reaction medium pushing the e q u i l i b r i u m to the r i g h t , o ii RCH2X + Nal 1 RCH 2I + NaX Chlorine and bromine exchange may be performed but mixtures of products are u s u a l l y observed. Secondary and t e r t i a r y halides may exchange, but at AO A l a greatly reduced rate compared to primary halides . Schim has used methanol as a solvent to achieve iodine exchange at a secondary p o s i t i o n : C 5H UCHCH + NaT — ~ ) CgH JHCH 75% Br 3 1 Use of higher b o i l i n g and more polar solvents can speed up the reaction and increase y i e l d s but the procedure s t i l l works best f o r primary p o s i t i o n s . - 14 -NaT HMPA ) 100° 3 days 957. -&I HMPA ) 150° 3 days 7 5 % Miller"'"' kas used an extension of t h i s r e a c t i o n to convert t e r t i a r y and benzylic chlorides to the corresponding iodides using an excess of Nal i n CS^ at 20° with a trace of FeCl^. I n t e r e s t i n g l y enough, primary and secondary halides f a i l to react. 44 NaT F ^ r t 3 y c s 2 Y i e l d 90% Time 24 hours H 3 (f^J C H 2 1 (CH 3) 3CC1 JL^ (CH 3) 3CI 100% 95% 90% Bromine to chlorine exchange has recently been reported by Vida using s i l v e r d i f l u o r o c h l o r o a c e t a t e . 22 hours 10 hours 2 hours 45 ClfyflOAg y giyme 124° 2 4 h r 857. - 15 -163 Kagan and co-workers have recently used graphite modified S b C l 5 to promote ch l o r i n e exchange. In the absence of graphite c h l o r i n a t i o n occurs p r e f e r e n t i a l l y as shown below. cci 4 no graphite w5th graphite 1% 60% 98% 35% II no graphite with graphite " t 81% 18% 46 F i l i p p o and co-workers"*" have also shown that MoCI,- may be used to convert a l k y l f l u o r i d e s , bromides and iodides to the corresponding chlorides, T e r t i a r y , secondary and primary halides exchange with rearrangement of primary halides occurring. I -h 12% -CI 58% 47 Kauer has recently shown that iodine i n normally unreactive p o s i t i o n s w i l l r e a d i l y react with iodine monochloride to produce chlorides as shown below: - 16 -_ICL cci 4 25° 4 /1 The r e l a t i v e ease of carrying out the r e a c t i o n l e d Kauer to suggest that a bridgehead carbenium ion was not involved but rather the following mechanism was occurring: RI + 2IC1 ^ R " ^ S + X 2 A O > C 1 2 R-Cl + IC1 The above i s supported by the e a r l y work of T h i e l e ^ 8 who i s o l a t e d an unstable dichloroiodo complex from the r e a c t i o n of methyl iodide and IC1. CH 3I + IC1 CH 3IC1 2 ^ CH3C1 + IC1 The r e a c t i o n to replace halogen by f l u o r i n e at unactivated centres has 4 9 been found to be d i f f i c u l t and to require more vigorous conditions Anhydrous s i l v e r f l u o r i d e has been used to synthesize the four p o s s i b l e bridgehead adamantyl f l u o r i d e s i n good y i e l d s " ^ . Muller has a l s o used i t to exchange F f o r CI i n the diphenylbenzocyclopropene system as w e l l 5 1 . Ad (Br) Ad- (F) x x = 1,2,3,4 60 - 80% O e r a AgF_> - 1 7 -Thus there are many d i f f e r e n t methods to interchange halogen atoms but u n t i l r e c e n t l y no one general procedure to e f f e c t complete exchange i n both d i r e c t i o n s ( i . e . CI —)> Br > I as w e l l as I > Br } CI). 52 This has been developed by Pincock and co-workers " for the bridgehead p o s i t i o n s of adamantane, bicyclo|j2 . 2. 2J octane and b i c y c l o |^2 . 2 . ij heptane. The fast and e f f i c i e n t exchange involves the i n s i t u generation of the desired Lewis acid c a t a l y s t from aluminum f o i l and bromine i n a , halogenated solvent. Mono and t e t r a s ubstituted adamantanes were r a p i d l y exchanged i n high y i e l d s . The smaller r i n g systems required more vigorous conditions but s t i l l proceeded i n good y i e l d s . In the case of iodinated solvents the y i e l d s were lower due to side r e a c t i o n s , mainly reduction and polymerization. Bridgehead Free Radical Chemistry Unlike i o n i c reactions which proceed v i a exclusive formation of the bridgehead carbenium ion, free r a d i c a l reactions of adamantanes y i e l d both secondary and t e r t i a r y products. For t h i s reason l e s s work has been done on the free r a d i c a l chemistry of the diamonoid hydrocarbons; the complex mixtures of products are often very d i f f i c u l t to separate and analyze completely. One of. the e a r l i e s t studies involved the free r a d i c a l c h l o r i n a t i o n of CC1. 0.63 -• 18 -In CCl^ a f a i r amount of p o l y c h l o r i n a t i o n was also observed but the i d e n t i t y of the products was not established. 54 Oda and co-workers have also shown t h i s competition between bridge and bridgehead abst r a c t i o n m the r e a c t i o n of adamantane with benzoyl peroxide and o x a l y l c h l o r i d e . Upon methanolysis an 82% y e i l d of the methyl esters was achieved (separable by d i s t i l l a t i o n ) . 55 45 Studies by Tabushi^^ have established that the bridgehead adamantyl r a d i c a l (a) was more r e a d i l y formed than the bridge r a d i c a l (b). He examined the competitive free r a d i c a l halogenation of adamantane with benzoyl peroxide at 90° i n various solvents. - 19 -Table I Free Radical Halogenation of Adamantane Reagent Solvent 1-C1 2-C1 1-Br 2-Br NBS C 6H 5C1 CH 2Br 2 CC1. 4 BrCCl„ CH 2Br 2 CC1. 4 BrCCl, 45 55 75 25 89 11 5 85 10 Experiments under 0 2 showed that only the bridgehead r a d i c a l (a) could be trapped to form 1-adamantanol, i . e . i t was long enough l i v e d to allow competition between halogen exchange and trapping by oxygen. The r e s u l t s i n Table I also showed that s t e r i c e f f e c t s were important; with the b u l k i e r H abstractors (-CHBr2 and -CCl^) more bridgehead products were observed. Further studies with the Hunsdiecker r e a c t i o n of 1 and 2-adamantane carboxylic acids showed the bridgehead r a d i c a l to be l e s s d i s c r i m i n a t i n g i n 56 i t s reactions H g O / B r 2 > C C I 4 - r 10 n 10 (Later work showed that i n the case of the bridgehead a c i d , halogen exchange v i a HgCl 2 was o c c u r r i n g 5 5 and that the r a t i o before exchange was a c t u a l l y 1.3:1.0; the secondary system did not undergo exchange). Thus the secondary r a d i c a l s e l e c t i v e l y picked up a bromine atom while the bridgehead - 20 -r a d i c a l preferred to p u l l a c h l o r i n e atom from the solvent. This suggests that the secondary (bridge) r a d i c a l i s a c t u a l l y the more s t a b l e . This low s e l e c t i v i t y of bridgehead r a d i c a l s has also been shown by the same reaction with B r 2 and HgO i n CCl^ on bicycloJ2.2. 2J octane-1-carboxylic a c i d " ^ +• B r 68% 3 2 % The a c t u a l competition between secondary and t e r t i a r y r a d i c a l s u s u a l l y depends on the nature of the ab s t r a c t i n g agent. In some cases only 58 bridgehead products are found. B i l l u p s has found s e l e c t i v e bridgehead abstrac t i o n i n adamantane by the use of nitrogen c a t i o n r a d i c a l s . R2NHCl H 2 S04 20 C I 36 62 However, t h i s s e l e c t i v i t y may be due i n part to the possible formation of bridgehead carbenium ions i n the strongly a c i d i c reaction medium. - 21 -No trace of secondary products were found from the carbene addition 59 to adamantane u t i l i z i n g a phase transfer agent . C l - P 3 KOH y R4NCI CHCI-Selective bridgehead r a d i c a l formation was also observed i n the photoacetylation of adamantane 6 0 as well as diamahtane 6 1. (CH3CO) 5.5 1 However, attack on po l y c y c l i c hydrocarbons by nitrenes resulted i n 62 both secondary and t e r t i a r y products as shown by the following reaction : 0 0 R'-CH3 + ROCN — > R o t i m-CH^R 1 From th i s reaction the r e a c t i v i t i e s of the various positions was determined, ( r e l a t i v e to cyclohexane = 1.0) r\2 4 4 X 7 6 Thus the r e l a t i v e rates of reaction for the bridgehead positions were - 22 -1.0:0.3:0.07 f o r adamantyl to b i c y c l o o c t y l to b i c y c l o h e p t y l . The corresponding r a t i o s f o r bridgehead bromide s o l v o l y s i s (carbenium ion -3 -10 intermediate) were 1.0:10 :10 . Thus a free r a d i c a l may be formed more r e a d i l y than a carbenium ion at the bridgehead of the smaller r i n g systems. 63 Owens has also found that free r a d i c a l bromination with BrCCl^ leads mainly to bridgehead products (both halogenation and halogen replacement). Further studies with photochemically generated Br atoms i n CCl^ showed that mixed secondary and t e r t i a r y products r e s u l t e d but no product analysis was performed. X=Bror CJ Y=CH3F.CI (Br - 23 -Wynberg""" has reported an i n t e r e s t i n g study i n which competition between free r a d i c a l and carbenium ion intermediates was involved. Kolbe e l e c -t r o l y s i s of carboxylic acids normally follows the mechanism shown below: RC0 2~ — — > R* 1. 2R* ) R - R 2. R- > R + ^ ^ > ROR' 3. In most cases the normal product i n high y i e l d i s the dimer. However, i n the case of adamantyl acids the following r e s u l t s were found. 7 0 % 0 Here the intermediate bridgehead free r a d i c a l r e a d i l y l o s t an e l e c t r o n to y i e l d carbenium ion products e x c l u s i v e l y while the secondary acid gave both c a t i o n i c and free r a d i c a l products. Therefore, i n cases where a competition between c a t i o n i c and free r a d i c a l pathways e x i s t s the bridgehead substituted adamantanes prefer to react v i a the c a t i o n i c one. Photochemistry of A l k y l Halides The absorption of u l t r a v i o l e t energy by a l k y l halides has received extensive study but i n nearly a l l cases involved homolytic carbon-halogen bond cleavage which led to free r a d i c a l derived p r o d u c t s ^ . Aromatic 67 halide photochemistry has been examined only recently and i n some cases - 24 -photochemical n u c l c o p h i l i c reactions are observed as w e l l as reduction. 68 In the only study of comparative r e a c t i v i t y of h a l i d e s , Pinhey found two rea c t i o n pathways for the excited aromatic h a l i d e . QH H •X H x~^ H. R = i P r X = CI X = Br X = I 62 9 0 19 73 82 He a t t r i b u t e d the increase i n the amount of reduction product to the decreasing strength of the C-X bond which would f a c i l i t a t e homolytic cleavage, In a s i m i l a r study, Bunce and co-workers examined the photochemistry of 69 a s e r i e s of halogenatednaphthalenes i n methanol hi? 4 CH 3 OH X = F X «' CI Br 70 99 75 52 25 48 However, Kropp has shown that not a l l a l k y l h a l i d e s react v i a a free r a d i c a l pathway. In the 2-norbornyl system, completely d i f f e r e n t products - 25 -were observed from the i r r a d i a t i o n of the iodide and bromide i n d i e t h y l ether. Thus the norbornyl iodide appeared to react v i a an " i o n i c type" intermediate while the bromide reacted i n a free r a d i c a l manner. Further research on bridgehead h a l i d e s ^ revealed that competitive i o n i c and free r a d i c a l pathways were involved. X = Br 55 35 X = I 12 76 I t was envisaged that i n i t i a l e x c i t a t i o n led to the formation of a r a d i c a l p a i r which reacted v i a two modes. I t could e i t h e r undergo electron t r a n s f e r to y i e l d an ion p a i r which underwent n u c l e o p h i l i c attack by the solvent or hydrogen abstraction to y i e l d the hydrocarbon. This was supported X = Br X = I 30 1 AO 47 19 41 T h u s t r a p p i n g o f t h e r a d i c a l p a i r b y 0^ c o u l d f a v o u r a b l y c o m p e t e w i t h e l e c t r o n t r a n s f e r t o t h e i o n p a i r . S i n c e r e a c t i o n s a t s m a l l r i n g b r i d g e h e a d s a r e r a r e , s l o w , a n d u s u a l l y i n e f f i c i e n t , a n d s i n c e i n t e r c h a n g e o f a l l h a l o g e n a t o m s h a d n o t b e e n a c c o m p l i s h e d , t h e i n i t i a l r e s e a r c h r e p o r t e d i n t h i s t h e s i s w a s c o n c e r n e d w i t h d e v e l o p i n g a n i m p r o v e d m e t h o d o f i n t e r c o n v e r t i n g b r i d g e h e a d h a l o g e n a t o m s . S p e c i a l e m p h a s i s w a s p l a c e d o n t h e i s o l a t i o n o f i o d i d e s w h i c h m i g h t b e p h o t o c h e m i c a l l y i n d u c e d t o r e a c t t o p r o d u c e a v a r i e t y o f b r i d g e h e a d s u b s t i t u t e d c o m p o u n d s i n s m a l l b i c y c l i c a n d t r i c y c l i c s y s t e m s . T h e i r r a d i a t i o n o f t h e d i i o d i d e s w o u l d a l s o b e e x a m i n e d f o r a n y t r a n s i e n t a p p e a r a n c e o f s t r a i n e d p r o p e l l a n e t y p e i n t e r m e d i a t e s s u c h a s s h o w n b e l o w : F i n a l l y , t h e p h o t o c h e m i s t r y o f b i c y c l i c a n d t r i c y c l i c b r i d g e h e a d c h l o r i d e s , b r o m i d e s , a n d i o d i d e s w o u l d b e e x a m i n e d i n o r d e r t o d e t e r m i n e i f c o m p e t i n g f r e e r a d i c a l a n d i o n i c t y p e r e a c t i o n p a t h w a y s w o u l d b e f o u n d a s w i t h t h e a r o m a t i c h a l o g e n c o m p o u n d s . - 27 -RESULTS In t h i s section a b r i e f account of the experimental r e s u l t s w i l l be presented with l i t t l e i n t e r p r e t a t i o n . A more complete a n a l y s i s of the data w i l l be found i n the DISCUSSION s e c t i o n . I Halogen Exchange Since a r e c e n t l y published method of halogen exchange gave low y i e l d s 52 of iodides , the development of a milder but more e f f i c i e n t system was sought. The i n s i t u generation of aluminum iodide from aluminum f o i l and elemental iodine i n r e f l u x i n g carbon d i s u l f i d e was found to produce a very a c t i v e c a t a l y s t which converted f l u o r i d e s , c h l o r i d e s and bromides to the corresponding iodide i n high y i e l d . Once the aluminum iodide was formed, the s o l u t i o n was cooled down to room temperature, 0°, or -50°, depending upon the nature of the halogen compound. The substrate was then added and the exchange was complete within one minute. The same solvent was used to i n i t i a t e bromine exchange as w e l l ; i n t h i s case the aluminum bromide was generated from aluminum f o i l and l i q u i d bromine. For c h l o r i n e exchange the aluminum c h l o r i d e was generated from aluminum f o i l and gaseous c h l o r i n e i n chloroform. Unfortunately, the use of carbon d i s u l f i d e as solvent l e d to e x c e l l e n t y i e l d s of elemental s u l f u r , while the use of carbon t e t r a c h l o r i d e as a solvent produced s u b s t a n t i a l amounts of hexachloroethane. Primary, secondary and t e r t i a r y h a l i d e s were a l l found to exchange r e a d i l y while aromatic halides were i n e r t under the r e a c t i o n c o n d i t i o n s . 19 The s t r u c t u r e s 0 ^ t n e halogenated adamantanes were v e r i f i e d by nmr a n a l y s i s - 28 -78% Rearrangement of secondary to t e r t i a r y p o s i t i o n s was found to occur t = 5 hr r a t i o s : 1 3 6 t = 22 hr r a t i o s : ! 5 1 Racemic 2-bromooctane was found to produce an 85% y i e l d of the corresponding iodide. When (+)-2-bromooctane was used (f_o<J = +29.4 op t i c a l purity 66.5%) racemization was the major reaction pathway at room temperature; however, as the temperature was lowered the amount of inversion product increased as shown below. Temperature 25° 0° -53° LVO D Enantiomeric Excess -65 1 0.0 -2.2 -8.7" -9.8L 0 5.1% 20.4% 23.0% Exchange of c i s and trans-4-t-butylcyclohexyl chloride was also found to be temperature dependent} however, both isomers yielded the same cis/trans mixture of iodides at various temperatures as v e r i f i e d by nmr analys - 3 0 -The ease of the exchange reaction f o r bridgehead halides was found to 2 6 follow the observed order for the s o l v o l y s i s of bridgehead bromides . That i s , the adamantyl bridgehead exchange was extremely f a s t , the 1-norbornyl system very slow and the 1 - b i c y c l o o c t y l intermediate i n r e a c t i v i t y . A more de t a i l e d analysis of these r e s u l t s w i l l appear i n the DISCUSSION sect i o n . t=30 sec t = l 5 hr t = 4 days X = C I Y = I This method of exchange using aluminum h a l i d e was compared to the use of f e r r i c c h l o r i d e i n carbon d i s u l f i d e . This f e r r i c c h l o r i d e r e a c t i o n was found to be much slower and to require a large excess of Lewis acid to achieve complete c h l o r i n e exchange. Because of t h i s r e l a t i v e l y decreased a c t i v i t y , however, i s o l a t i o n of intermediate mixed halides was p o s s i b l e . 4 0 hr 3 2 - 31 -II Photochemistry of Halides A) Photolysis of Bridgehead Halides i n Alcohols 66 66a As found f o r the aromatic halides ' , great d i f f e r e n c e s i n the type and r a t i o of products occurred f o r i r r a d i a t i o n of bridgehead c h l o r i d e s , bromides and iodides as shown below. X » I 5% 95% X = Br 20 - 30% 70 - 80% X = CI 100% A comparison was made with the thermal reaction of 1-iodo and 1-bromo-adamantane i n r e f l u x i n g methanol. A f t e r s i x hours the reactions were 35% and 10% completed and 90% and 60% completed a f t e r 24 hours. The photo-chemical reactions at approximately 35° C were completely f i n i s h e d . a f t e r 2% and 8 hours r e s p e c t i v e l y . At room temperature 1-bromoadamantane showed no re a c t i o n a f t e r three weeks, while 1-iodoadamantane was 30% consumed. I r r a d i a t i o n of d i and t r i i o d i d e s gave good y i e l d s of the corresponding ethers. I r r a d i a t i o n of d i - and tri-bromoadamantane on the other hand - 32 -y i e l d e d mixtures of mono-, d i - and t r i a l k o x y adamantanes. X = I t = 6 hr — — 96% X = Br t = 24 hr 19% 50% 22% No 1,3-dehydroadamantane intermediates were detected, rather monitoring by g l c indicated that a stepwise r e a c t i o n was occurring. Workup of the photochemical reaction of dibromoadamantane i n methanol before completion gave two intermediate bromo-adamantanes which reacted upon furt h e r i r r a d i a t i o n to y i e l d the observed products. - 33 -The same trends were found f o r the 1,4-diiodonorbornyl system, except that a higher percentage of hydrogen t r a n s f e r r e l a t i v e to s u b s t i t u t i o n by OCH„ was observed. X = Br 31% 69% X = I 6% 94% The re a c t i o n of adamantyl bromides could be stopped by the use of a Pyrex f i l t e r ; iodides continued to react through Pyrex. B) Production of Amides by the Photolysis of Bridgehead Halides i n A l k y l N i t r i l e s With the use of a l k y l n i t r i l e s as solvents, good y i e l d s of the corresponding a l k y l amides were i s o l a t e d . Here only the iodides were used; i r r a d i a t i o n of the bromides also produced amides but at a much slower r a t e . The bridge and bridgehead iodides reacted cl e a n l y to y i e l d the corresponding amides. 1,3-Diiodoadamantane reacted to y i e l d the iodoamide which on f u r t h e r i r r a d i a t i o n y i e l d e d the diamide with no trace of the monoamide. The r e a c t i o n of the norbornyl iodides produced a s i m i l a r pattern, except that only the monoamide could be i s o l a t e d . In a l l cases i t was found that the rea c t i o n was very slow and incomplete i f extremely dry solvents were used. The best r e s u l t s were obtained by adding 2 - 3 drops of water to the s o l u t i o n of the iodide i n the a l k y l n i t r i l e s . C) Photolysis of Bridgehead Halides i n Amine Solvents The i r r a d i a t i o n of 1-iodoadamantane i n alcohols r e s u l t e d i n the formation of 1-alkoxyadamantanes, When the same reaction was repeated i n - 35 -diethylamine s o l u t i o n , none of the product corresponding to reaction at nitrogen was observed. Instead, the reduction product adamantane predominated with a small amount of coupling to the carbon atom c< to the nitrogen atom. ij H N E * 2 N- NH Et 807o . When the reac t i o n was repeated i n the presence of 0^ the only compound i s o l a t e d was 1-adamantanol i . e . the reduction pathway was being diverted by oxygen. Use of triethylamine or p y r r o l i d i n e as solvents l e d to the formation of adamantane i n greater than 90% y i e l d . The ad d i t i o n of 3,5-di-t-butyl-4-hydroxytoluene (a free r a d i c a l i n h i b i t o r ) to the reaction i n diethylamine and triethylamine slowed the reactions down and l e d to exclusive formation of adamantane. hfc? RNEt-no i n h i b i t o r Time of Reaction 2 hours added i n h i b i t o r R = H = Et 15 minutes R = H 9 hours = Et 6 hours However, i r r a d i a t i o n i n morpholine r e s u l t e d i n a 1:1 mixture of adamantane and the corresponding adamantylamine. t - 36 -D) Photolysis of Bridgehead Halides i i i Halogertated Solvents The photochemistry of the four bridgehead monohaloadamantanes was examined i n carbon t e t r a c h l o r i d e and bromotrichloromethane. I r r a d i a t i o n i n CCl^ l e d to the formation of 4 main products plus s u b s t a n t i a l amounts of hexachloroethane. + + 3 h r + x=r7CI,Br t race The structures were assigned on the basis of nmr analysis and i n the case of the svn and a n t i - 1 , 4 - d i c h l o r i d e s by comparison to authentic samples A more d e t a i l e d d e s c r i p t i o n w i l l be made i n the DISCUSSION s e c t i o n . In contrast, i r r a d i a t i o n using BrCCl^ as a solvent led to exclusive bromination of the bridgehead p o s i t i o n s (longer r e a c t i o n times eventually resulted i n the formation of some secondary products). 34 BrCCI-x=fTCI,B r + Also there was no evidence for any hexachloroethane formation. - 37 -DISCUSSION A) Halogen Exchange Since they are r e a d i l y a v a i l a b l e , the brominated adamantanes were used as s t a r t i n g materials i n the Lewis a c i d catalyzed exchanges of the other halogens. Reaction of adamantane and 1,3-dimethyladamantane i n r e f l u x i n g bromine f o r three h o u r s 1 5 produced a near q u a n t i t a t i v e y i e l d of the corresponding bridgehead monobromides. Due to the p r e f e r e n t i a l formation of the bridgehead carbenium ion, no trace of any secondary isomers was observed. B r B r " > 95% 91% The i n t r o d u c t i o n of two or more bromine atoms required the presence 73 of a Lewis a c i d c a t a l y s t . Many d i f f e r e n t research groups have used various mixtures of co - c a t a l y s t s to e f f e c t t h i s s u b s t i t u t i o n , but often with 2 2 irreproduceable r e s u l t s . I t has been found that a d d i t i o n of very small amounts of " a c t i v e " aluminum bromide 7^ under c a r e f u l l y c o n t r o l l e d conditions gave good y i e l d s of the higher brominated adamantanes. A r-AIRn, Br-The reaction most l i k e l y proceeds v i a the formation of the complex Br AlBr^ . The p o s i t i v e bromine abstracts a hydride ion from adamantane to - 38 -form the bridgehead carbenium ion which abstracts Br from the solvent to y i e l d another bromine cat i o n . Olah has found^"* that the 1-adamantyl cation i s s t a b i l i z e d by i n t e r a c t i o n of the cation carbon with the back lobes of the other three bridgehead carbon atoms. Replacement by Br for H at these centers would decrease the s i z e of the back lobes and lessen t h i s s t a b i l i z a t i o n e f f e c t . Thus further a d d i t i o n of bromine should be slower due to the decreased s t a b i l i t y of the intermediate bridgehead carbenium ion. Consistent with t h i s inductive e f f e c t i s the experimental observation that the reaction to form the tetrabromide i s very slow, r e q u i r i n g seven days i n a sealed tube at 170°. Although the y i e l d of 1,3,5,7-tetrabromoadamantane i s low as a r e s u l t of disproportionation reactions which lead to the formation of t h i c k t a r s , the four 1-bromo, 1,3-di, 1,3,5-tri, and 1,3,5,7-tetrabromoadamantanes were r e a d i l y a v a i l a b l e and were used as the s t a r t i n g points for the halogen exchange studies. The i n i t i a l work was concerned with a mild method f o r the i s o l a t i o n of bridgehead iodides, for use i n exchange and p h o t o l y t i c studies. Pincock and 52 co-workers had found that i n halogenated solvents low y i e l d s of the iodides were obtained, side reactions leading to reduction and to polymerization predominated. This was probably due to the large excess ( r e l a t i v e to substrate) of aluminum iodide present i n the reaction mixture. Since i t was desired that the exact amount of c a t a l y s t present be known, a nonhalogenated solvent, carbon d i s u l f i d e , was chosen f o r further study. In t h i s solvent the preparation of a s o l u t i o n of extremely a c t i v e aluminum iodide was r e l a t i v e l y f a c i l e . Aluminum f o i l was torn into small pieces (with f r e s h l y washed and dried fingers) to expose fresh metal and placed with elemental iodine i n a - 39 -round bottomed fla s k . The f l a s k was then heated at 80 w for a few minutes to vapourize a few of the iodine c r y s t a l s . At this point i t was noted that dark specks were forming on the aluminum f o i l . The carbon d i s u l f i d e was added and the purple solution was s t i r r e d under r e f l u x for 45 minutes. At the end of t h i s time the purple colour had been replaced by a l i g h t pink and most of the aluminum f o i l had been consumed. The solution of the active catalyst was then cooled down to room temperature and the brominated adamantane added. I t was soon found that an excess of aluminum f o i l was es s e n t i a l to the reaction. Excess iodine led to polymerization as the predominant pathway with low y i e l d s of the desired iodides. I n i t i a l studies with a 4:1 r a t i o of iodine to 1-bromoadamantane with an excess of aluminum f o i l led to rapid Iodine exchange but upon standing at room temperature side reactions also occurred. After a great deal of time was spent testing reaction times and substrate r a t i o s i t was found that the best re s u l t s were obtained u t i l i z i n g an aluminum f o i l to iodine to 1-adamantyl bromide molar r a t i o of 4:0.75:1.0. The exchange was complete after 1 minute at room temperature and very l i t t l e decomposition occurred upon standing at room temperature. I t was l a t e r discovered that even better y i e l d s could be rea l i z e d by running the reaction at -50°. Here again the exchange was complete a f t e r 1 minute. Thus i t was found that t h i s procedure produced a very active and mild iodine exchanging ca t a l y s t . For example, tetrabromoadamantarie could be completely converted to the tetraiodide i n 1 minute at room temperature, unlike the reaction using a halogenated solvent which required more forcing * 5A conditions . This in. s i t u generation of aluminum iodide was used to prepare ~ 40 -a l l the possible adamantyl and 1,3-dimethyladamantyl bridgehead iodides. The method was extended to the exchange of other halogen atoms. As a res u l t of these reactions, as described below, the 16 diff e r e n t mono, d i , t r i and tetrahaloadamantanes were made available. A study of the halogen 13 effects on the C spectra of these molecules was made, the results of which w i l l appear l a t e r on i n t h i s section. Bromine exchange was not required as a resul t of the ease of synthesis of the brominated adamantanes. However, i t was found that substitution of l i q u i d bromine for elemental iodine i n the above i n s i t u generation of A l l ^ led to a solution of very active aluminum bromide. A halogen exchange reaction could then be performed to produce high y i e l d s of bromides from other halides. Preparation of the bromide catalyst was s l i g h t l y d i f f e r e n t from that of the iodide. The aluminum f o i l and bromine were mixed with 2 ml of and allowed to stand u n t i l the f o i l began blackening. (With no solvent present the exothermic reaction resulted i n the evolution of large amounts of B^) . The rest of the solvent was added and the dark brown solution s t i r r e d under r e f l u x for 1 hour which resulted i n a l i g h t orange solution. This was cooled to room temperature and the bridgehead halide added as before. Chlorine exchange was investigated by extending the reaction to the i n  s i t u generation of active aluminum chloride. Bubbling chlorine gas through a mixture of aluminum f o i l and CS^ at 0° led to a yellow solution. To t h i s was added a small c r y s t a l of i n order t o . i n i t i a t e an exothermic reaction which consumed most of the aluminum f o i l . Upon cooling to 0°, 1,3-dibromo-adamantane was added and the reaction worked up after 2 minutes. Analysis of the solution by glc indicated that the desired exchange had occurred but - 41 -upon' evaporation a large amount of a dark yellow s o l i d was- isolated. " * -•'< To establish what was taking place the reaction was repeated in the absence of the adamantyl dibromlde. Again a yellow s o l i d was obtained, which upon glc analysis at long retention times proved to be Id e n t i c a l to elemental s u l f u r . In order to eliminate t h i s production of s u l f u r , the solvent system was changed from CS^ to CCl^,. The reaction was repeated under the same conditions with C l ^ gas. A dark black solution was obtained to which the adamantyl dibromide was added. Workup th i s time again resulted i n the ; isolation' of a yellow s o l i d . Repetition i n the absence of the bromide again resulted i n the same yellow s o l i d which was shown to be i d e n t i c a l to hexachloroethane. Therefore, after major side reactions which successively oxidized the CS 2 and r a d i c a l l y coupled the CCl^, i t was decided to f a l l back upon the 5 i solvent used e a r l i e r , i . e . chloroform. The use of Cl^ with aluminum f o i l i n CHCl^ generated a very active catalyst which produced chlorides i n high y i e l d s at room temperature at a faster rate than observed for the A l C l ^ generated previously by Pincock and co-workers"^ For example, the conversion of 1,3,5,7-tetrabromoadamantane to the tetrachloride was complete i n 15 minutes at room temperature while the previous method required 20 hours. For f l u o r i n e exchange AgF was used as reported earlier"'*"'. However, much better yi e l d s could be isol a t e d by drying the s i l v e r f l u o r i d e under vacuum at 140° for 5 hours before use. This eliminated the formation of alcohols and resulted i n 70 - 85% y i e l d s of the corresponding f l u o r i d e s . ti Therefore, complete interchange of any halogen at the bridgehead positions of any mono, d i , t r i or tetrahaloadamantane could be effected. Since - 42 -the formation of iodides was to be used for the production of s t a r t i n g materials f o r photochemical studies, the iodine exchange rea c t i o n was studied f u r t h e r . I t was found that even the r e l a t i v e l y i n e r t C-F bond would react with t h i s c a t a l y s t system to y i e l d the corresponding i o d i d e . Al T. 2 — } Next of i n t e r e s t was to determine i f primary and secondary c y c l i c and a c y c l i c halides could also be exchanged to the corresponding iodides without the e l i m i n a t i o n to o l e f i n s , rearrangement and/or polymerization which may 44 proceed with these systems. M i l l e r has recently found a method of converting t e r t i a r y and b e n z y l i c chlorides to the corresponding iodides using Nal i n carbon d i s u l f i d e at room temperature with a trace of FeCl^ as c a t a l y s t . The r e a c t i o n proceeds i n high y i e l d s but i s quite slow ( 10 -72 hours). The heterogeneous re a c t i o n was thought to occur v i a a c l o s e l y held complex or ion p a i r . RCl + FeCl + I~ — ) R; C 1 " FeCl RI + F e C l 3 + CI 3 The r e a c t i o n s t i l l proceeded using mercuric c h l o r i d e i n place of f e r r i c c h l o r i d e but f a i l e d completely i f a soluble iodide (nBu^NI) was used. The use of A l C l ^ i n place of FeCl^ gave no exchange at a l l . I n t e r e s t i n g l y , the reaction f a i l e d completely f o r primary or secondary chlorides which e a s i l y 39 react v i a the F i n k e l s t e i n reaction RCH2C1 + Nal — ) RCH 2I + NaCl The use of aluminum iodide generated i n s i t u was found to r e a d i l y exchange primary and secondary h a l i d e s . However, i n most cases the observed - 43 -y i e l d s were lower than for the t e r t i a r y halides. A J L _ X cs-t. 0° 2 — ) 74% a 78 % 68 7. Analysis of the product from the reaction of 1-chlorobutane by nmr showed no trace of any rearrangement products. The exchange on 2-bromooctane produced 2-iodooctane again with no observeable rearrangement. The reaction of o p t i c a l l y active bromide was found to be temperature dependent. The exchange of (+)-2-bromooctane (obtained from Norse Chemical Zo.[cA\ = 29.4° o p t i c a l purity = 66.5°/J^) was performed at 4 d i f f e r e n t temperatures with the amount of o p t i c a l l y active iodide increasing with decreasing temperature. i r I 76 Temperature 25° -53° 0.0 -2.2V -65^  -9.8 Enantiomeric Excess 0 5.1% 20/4% ' 23.0% * Even at low temperatures the major product arose via racemization with 15% due to inversion at -65 . Complete racemization may imply that a free carbenium ion i s present which may undergo attack by I from either side or racemization may arise from repeated exchange without the presence of a carbenium ion. A s i m i l a r exchange on c i s and ' trans 4-_t_-butylcyclohexyl chloride also yielded iodides, the r a t i o of which were temperature dependent. The same r a t i o (determined by nmr integration) of iodides was formed from either stereoisomeric chloride at various temperatures. This r e s u l t suggested a common intermediate, l i k e l y a t i g h t l y held ion p a i r . c i s 35 65 The reactions with the t_-butyl cyclohexyl chlorides were worked up after 1 minute (analysis of the reaction at -55° over a period of 1 hour indicated that the r a t i o of products did not change). By using the above r a t i o s at the various temperatures, the energetics of the cis-trans mixtures could be determined. From K = eq.uat I a x i a l I A G ° 298 «= -0.55 kcal/mole and from a plot of log K versus 1/T the following values could be determined. A H = +2.34 kcal/mole A S ~ +9.98 eu ' ' : ' .v - 45 -The value of G° compares well with results found by other researchers as showa below: X = CN ^G° 339 = -0.25 kcal/raole 7 7 X = OH AG° 298 = -0.54 kcal/mole X = C0 2Et AG° 298 = -1.0 kcal/mole 7 9 Therefore, for the iodides and the other cis-trans isomers the equatorial isomer i s more stable at higher temperatures due to i t s greater degree of freedom (/\S overides the contribution by/\H). The above res u l t s from the o p t i c a l l y active 2-octyl and c i s and trans 4-t_-butylcyclohexyl systems seemed to point to an ion-pair type intermediate rather than a free carbenium ion. Rearrangement as we l l as o l e f i n i c products could be expected i f a free carbenium ion was involved. This marked resistance to rearrangement was also observed with the exchange on the secondary p o s i t i o n of adamantane. The exchange of 2-bromo-adamantane.at 0° led to a 95% y i e l d of the corresponding secondary iodide. S t i r r i n g the solution at room temperature for 5 hours produced no change. However, r e f l u x i n g the solution gradually led to the formation of the bridgehead isomer. A small amount of adamantane was observed as well as a t = 22 hr 1 5 1 An increase i n the concentration of the solution led to an increase i n the rate of the rearrangement. This i s i n accord with s i m i l a r apparent 80 1,2-shifts i n the adamantyl system. Dir e c t intramolecular 1,2-shifts are believed to be strongly i n h i b i t e d i n these systems. For a f a c i l e exchange to occur a dihedral angle of 0° between the vacant p o r b i t a l and the C-R bond (R = migrating group) would be desired. In the adamantyl system the dihedral angle f o r the t e r t i a r y cation i s 60° while f o r the secondary cation i t i s 90°. Therefore these 1,2-shifts are thought to be intermolecular i n nature. 80 This i s supported by work on the Koch-Haaf rea c t i o n of 2-adamantanol. The r a t i o of t e r t i a r y to secondary product was found to be concentration dependent which i s expected f o r an intermolecular process. H HCOOH v H 2 S 0 4 7 volume of H-SO, 2 4 30 ml 52 ml 300 ml 1000 ml C 0 2 H % o 65 86 99.5 7o 100 35 14 0.5 A s i m i l a r concentration dependence was observed f o r the interconversion 80 of 1- and 2-adamantanol i n concentrated H„S0,. . 2 4 For the apparent 1,2-methyl s h i f t s an intramolecular mechanism has been - 47 -81 14 found to e x i s t . S p e c i f i c a l l y l a b e l l e d 2- C adamantane was treated with A l B r 3 i n CS 2 for 14 days at 25 . This l e d to 1.9% of carbon scrambling. However, treatment for 8 hours at 110° led to 78% scrambling as shown v i a the following mechanism. RH ^ R H . A s i m i l a r mechanism was found f o r the 2 to 1-methyladamantane 82 interconversion . In t h i s case, however, the presence of the methyl groups enhanced the r e a c t i v i t y ; the reaction was complete a f t e r 5 days at 25°. The same type of rearrangement has been found f o r the biadamantane 83 84 system as w e l l . S t i r r i n g a s o l u t i o n of e i t h e r 1,1' or 2,2'-biadamantane with A l B r 3 i n cyclohexane at 60° leads to the same mixture of three isomers at equilibrium. o r A|Rp 60° 3—) 1,1' t 2 ; 2 ' t-1,2' 25 70 This supports the c a l c u l a t e d values of the s t r a i n energy f o r the 3 biadamantanes^"'. Table I I S t r a i n Energy of Isomeric Biadamantanes S t r a i n Energy kcal/mole 1,1'-biadamantane 2,2'-biadamantane 1,2'-biadamantane adamantane 21.46 19.70 23.04 6.87 - 48 -Si m i l a r complex mixtures have been observed from the Lewis a c i d 86 catalyzed bromination of 1,1-biadamantane . However, the products have not been f u l l y characterized. In s p i t e of the p o s s i b i l i t y of t h i s rearrangement, the re a c t i o n of i n s i t u generated A l C l ^ or A l l ^ with 3 , 3'-dibromo-l,l'-biadamantane produces the corresponding c h l o r i d e and iodide with no rearrangement. The same i s true f o r the s i l v e r f l u o r i d e promoted exchange. X = F 76% f j ^ "7 X = C l 70% ?2 V ^ x ^ 7 " 2 x = 1 7 6 % Thus i t was found that secondary and primary h a l i d e s , as well as bridgehead h a l i d e s , could be exchanged i n high y i e l d s under very mild conditions. Aromatic halides were found to be i n e r t under the re a c t i o n conditions. In systems prone to rearrangement or e l i m i n a t i o n (e.g. cyclohexyl,1-butyl, 2-octyl halides) the unrearranged products could e a s i l y be i s o l a t e d . The ease of the exchange was also found to p a r a l l e l the expected r e l a t i v e s t a b i l i t y of the corresponding bridgehead carbenium ion. The reaction of 1,4-dichlorobicyclo ^2.2. l j heptane to the d i i o d i d e proceeded i n low y i e l d s (45%) and required 4 days i n r e f l u x i n g carbon d i s u l f i d e (bp 46°). The large amount of polymeric material was due to the ten f o l d excess of, aluminum iodide required to t o t a l l y consume the s t a r t i n g m a t e r i a l . A more rapid reaction was observed by the use of r e f l u x i n g cyclohexane (bp 80°) as solvent. Here the d i i o d i d e was i s o l a t e d i n 74% y i e l d a f t e r 12 hours. The iodine exchange on 1,4-dichlorobicyc loJ2.2.2j oc tane was found to be i n t e r -72 mediate i n rate between the norbornyl and adamantyl systems as shown below. - 49 -c s 2 -50° 25' t=30 sec X= CI Y = I t*15hr ref 72 46° t = 4 days The ultimate t e s t of t h i s exchange method was on the very unreactive t r i p t y c e n y l system shown below: NaOH 80 mineral o i l t = 1 0 h o u r s N 0 A C T I O N re f t = 5 days NO REACTION r e f 87 88 280 89 The attempted iodine exchange on 9-chlorotriptycene f a i l e d i n r e f l u x i n g cyclohexane, d e c a l i n and para-xylene (3 f o l d excess of A l l ^ , s o l u t i o n s t i r r e d under r e f l u x f o r 4 days). In a l l cases the 9-chlorotriptycene was recovered unchanged, the darkening of the s o l u t i o n i n d e c a l i n and xylene was found to be due to reactions of the solvent with the aluminum io d i d e . No trace of the t r i p t y c e n y l iodide or reduction to the parent hydrocarbon was observed. This confirms the estimate that the bridgehead p o s i t i o n of 9 triptycene would be at l e a s t 10 times l e s s r e a c t i v e than the bridgehead P T 2d p o s i t i o n s of bicyclol2.2.2/ octane . - 50 -The major reason for t h i s extreme inertness i s due to the non-flexible 90 nature of the carbon skeleton. Theoretical work has suggested that bridgehead carbenium ions do not reach p l a n a r i t / , instead an optimum geometry i s achieved. This can be v i s u a l i z e d by examining the bridgehead 26 carbenium ion of adamantane . The angle at the bridgehead would prefer to o 2 be 120 , (sp hybridization) however as f l a t t e n i n g at th i s position occurs the nonbridgehead angles decrease i n size r e s u l t i n g i n increased s t r a i n . For 6 to be 120° <f) would have to decrease to 90° from 109.5°; i f no fl a t t e n i n g occurred G would be 109.5° as would <|> . Therefore a certain amount of bending could occur to make 8 = 113° and $ = 104° for an optimum geometry of lowest s t r a i n energy. I t i s therefore clear that i n systems where the molecule i s less f l e x i b l e the carbenium ion w i l l not be as stable and less l i k e l y to form. The triptycene system may be considered by examining the x-ray data. X = H 9 = 105.3° 4) = 113.1° r e f 9 1 X = Br 9 = 107.5° tj> = 110.7° r e f 9 2 Now i f one assumes the values for X = CI to be between those f o r X = H and X = Br i t i s apparent that i f f l a t t e n i n g of the bridgehead occurs to make 9 approach 120° then <J> must also approach 90°. However, unlike the adamantane case, <J» f o r the t r i p t y c e n y l system would prefer to be 120° 2 (since i t i s at an sp hybridized carbon atom). Any f l a t t e n i n g of the bridgehead w i l l increase the o v e r a l l s t r a i n energy by decreasing the value of <j) further away from i t s normal value of 120°. Therefore a consideration of angle s t r a i n alone suggests that the 9 - t r i p t y c e n y l carbenium ion would be very unstable and reluctant to form. The b i c y c l o £ 2 . 2 . 2 J o c t y l system i s not as strained and w i l l permit a 93 bridgehead carbenium ion more r e a d i l y 9 = 108.8° <j> = 110.1° This unreactiveness of the 9 - t r i p t y c e n y l system now leads to a more d e t a i l e d examination of the mechanism by which t h i s aluminum h a l i d e promoted exchange takes place. 44 M i l l e r ' s proposal of a loose complex of the Lewis a c i d and the substrate (see page 42) appears reasonable except that f o r the aluminum halide reactions there w i l l be no free I a v a i l a b l e as a r e s u l t of the excess aluminum f o i l present. M i l l e r also found that AIX^ did not react i n h i s - 52 -system. However, i f we consider i n i t i a l f r o n t side attack by the aluminum h a l i d e , a loose complex w i l l r e s u l t . R - X + A 1 I o r * p i d \ R-... i ' - A 1 I 2 o r R X - A l ^ ^ r\ i slow R-I + A1I„X ^ a p i d R + A1I_X~ This loose complex could e x i s t i n e q u i l i b r i u m with a t i g h t l y held i on p a i r composed of the bridgehead carbenium ion plus the aluminum h a l i d e anion. The concentration of t h i s ion p a i r at any one time would probably be quite small but once formed would r a p i d l y abstract an i o d i d e ion to produce the bridgehead iodide (or other ha l i d e depending upon which Lewis acid was being used). This t i g h t l y held ion p a i r would also explain why at room temperature no rearrangement of the 2-iodoadamantane (secondary iodide) to 1-iodoadamantane (bridgehead iodide) occurs and why e l i m i n a t i o n to o l e f i n s i n other systems i s minimized. Higher temperatures are required f o r the e q u i l i b r a t i o n of products and f o r any intermolecular rearrangement of the product, p o s s i b l y through more f u l l y formed carbenium ions. The d i f f e r e n c e i n rates of the adamantyl,bicyclo£2.2.ljheptyl, b i c y c l o [1>. 2.2] o c t y l and t r i p t y c e n y l systems (see page 49) also support the above mechanistic a n a l y s i s . A f a s t e r o v e r a l l r e a c t i o n would r e s u l t from the intermediary of a r e l a t i v e l y stable carbenium ion p a i r . The r e l a t i v e rates of the exchange are i n the same order as the rates of the s o l v o l y s i s of the bridgehead bromides (see page 2 of INTRODUCTION). However, a f u l l carbenium ion intermediate i s not l i k e l y because of the lack of rearrangement or e l i m i n a t i o n products as shown before. Also informative are the r e s u l t s of extended reaction times on the 1,4-dihalo-bicyclo/5.2.2 ^octane system. In t h i s case rearrangement of the r i n g system does occur to y i e l d mixtures of bicyclo£3.2. l ] o c t y l and bicyclo/^2.2. lj o c t y l - 53 -,. •. 7 2 products as shown below . Al Rrv CHB 80° Air.u r 3 2.5 t=24 hr. CIF2CCCUF C1\—/ 80 The above i s contrary to the r e s u l t s found by Olah from the re a c t i o n of l-chlorobicycloLT2.2.2]octane i n SbF 5 - SC^CIF at -78°. Reaction occurred i n s t a n t l y to form the b i c y c l o / 5 • 3. QJ - 1 - o c t y l c a t i o n . Shfv, SQ2CIF^ -78" The super acid r e s u l t s would tend to suggest that free carbenium ions are not involved i n the Lewis acid promoted halogen exchanges. The extended reaction times were also used i n an attempt to rearrange the bicyclo/5.2.l]heptyl to the bicyclo|3.1.lJheptyl system but without success. The rearrangement of the b i c y c l o o c t y l and not the b i c y c l o heptyl are i n d i r e c t l y supported by t h e o r e t i c a l c a l c u l a t i o n s on the parent hydrocarbons 85 by Schleyer and co-workers - 54 -Table I I I S t r a i n Energy of B i c y c l i c Systems Compound S t r a i n Energy kcal/mole 12.95 12.06 12.49 16.98 35.85 In addition to the d i f f e r e n c e i n carbenium ion s t a b i l i t i e s , the e f f e c t of Lewis a c i d i t y on the exchange reaction was also examined. One would expect aluminum halides to be better reagents as a r e s u l t of t h e i r greater 164 Lewis acid strength r e l a t i v e to f e r r i c h a l i d e s . However i n M i l l e r ' s 44 study A1C1.J was i n e f f e c t i v e as compared to FeCl^. A comparison of the two procedures in d i c a t e s that the i n s i t u generated A l l ^ i s much more r e a c t i v e . * *2 ) c s 2 0 ° FftCI3 NaT ) C S 0 25° t=30 sec; t=24 hr - 5 5 -As a complement to the above, a study was made of the a b i l i t y of FeCl^ versus i n s i t u generated A l C l ^ to promote exchange of bromine f o r c h l o r i n e . I t was found that FeCl-j was e f f e c t i v e but that both a large excess of the Lewis acid and longer r e a c t i o n times were required. CHCI3 o t=15min FeCl-C S 2 4 6 e t= 6hr Refluxing conditions were required to achieve complete exchange with FeCl^. One advantage, however, i s that room temperature reactions allowed the i s o l a t i o n of mixed halide species. FeCl* C $ 2 25* 40 h r t + 3 1 Therefore i t appeared that the strengths of the respective Lewis acids also a f f e c t e d the rate of the r e a c t i o n , the weaker FeCl^ r e q u i r i n g a longer time to achieve complete exchange. With e i t h e r FeX^ or AIX^ the same general mechanism should apply f o r the exchange of the bridgehead h a l i d e s . In the case of the bridge substituted isomers one might consider backside attack a l i k e l y p o s s i b i l i t y . - 56 -However, the reaction at the secondary carbon of adamantane by nucleophilic backside attack has been found to be r e l a t i v e l y unimportant due to s i g n i f i c a n t nonbonded interactions with the a x i a l hydrogen atoms as shown below: H Whiting has found that S N2 type reactions do not occur and the following tosylates solvolyze with excess retention over inversion. Elegant studies by Schley?.r and. co-workers have further indicated that s o l v o l y s i s of 2-substituted adamantanes does not involve n u c l e o p h i l i c attack. Adamantanes substituted i n the 2 posi t i o n solvolyze i n much the same fashion as the bridgehead isomers and completely d i f f e r e n t l y from usual secondary compounds. The most convincing evidence on th i s point has been presented i n a study of s o l v o l y s i s i n the presence of azide ion. When the addition of causes a rate enhancement and a corresponding a l t e r a t i o n i n the d i s t r i b u t i o n of products a bimolecular (S^2) type reaction may be f ,97 suspected Schleyer and co-workers have investigated the effect of azide ion on 98 the s o l v o l y s i s of 3 a l k y l derivatives i n 80% aqueous ethanol. - 57 -Table IV Effect of Added Azide on the Rate of.Solv o l y s i s % Yields Substrate NaN3 i i n 5 - 1 k x. 10 sec RN3 ROIL ROEt 1-adamantyl 0.00 12.6 0.0 49 51 bromide 0.02 13.0 0.4 41 58 0.01M 0.04 13.2 0.4 45 54 . 75° 0.06 14.2 0.6 43 56 2-adamantyl 0.00 1.94 0.0 71 29 tosylate 0.02 2.10 0.1 68 31 0.01M 0.04 2.17 0.4 66 33 75° 0.06 2.26 0.7 65 34 2-propyl 0.00 5.75 0 100 tosylate 0.02 8.27 31 69 0.01M 0.04 12.5 54 46 50° 0.06 16.9 65 35 Thus the 1 and 2-adamantyl compounds solvolyze i n the same:way with and without azide ion. Very l i t t l e adamantyl azide i s formed and only a small increase i n the rate of reaction i s observed. The "normal" secondary derivative reacts completely d i f f e r e n t l y which one would expect for an 3^2 type s o l v o l y s i s . Therefore, t'ue halogen exchange reaction should also proceed v i a the same pathway for both bridgehead and bridge halogens of the adamantane-ring structure. As a r e s u l t of the s t e r i c i n h i b i t i o n of backside attack at the secondary positions of adamantane i t was anticipated that various secondary and mixed t e r t i a r y and secondary adamantyl halides could be s e l e c t i v e l y exchanged. The 1,2-adamantyl dichlo r i d e was cleanly converted to the dibromide and diiodide with no trace of any of the other Isomers. * 2 M X = I 820/, 50' - 58 -The same reaction was repeated f o r the gem d i c h l o r i d e . In t h i s case rearrangement was the major pathway. At low temperatures the re a c t i o n could be quenched to y i e l d two dibromides e a s i l y separated by g l c . 20 70 The minor component was found to be the unrearranged gem dibromide, the major being the syn-1,4-dibromide (a small amount of the corresponding a n t i isomer was also present). The syn dibromide was c o l l e c t e d by g l c and 99 assigned on the basis of melting point and nmr chemical s h i f t s When the r e a c t i o n was repeated under iodine exchange conditions at low temperatures two products were again observed by g l c . However, the gem d i i o d i d e could not be i s o l a t e d . Upon preparative t i c or column chromatography only adainantanone plus a small amount of 2-iodoadamantane was obtained. The major product from the reaction was identified as syn-1.4-diiodo-adamantane on the basis of i t s similar nmr to the syn-1.4-dichloride and ayo.-l,4-dibromide (see nmr DISCUSSION section). In this case there was no trace of any of the anti-1,4 isomer by glc or nmr analysis. When the reaction was repeated at room temperature a 70% - 59 -y i e l d of the syn-1,4-diiodide was r e a l i z e d . The corresponding chlorine exchange on the gem dibromide was also examined. In this case an 87% y i e l d of the 1,4-dichlorldes was observed. The product consisted of 81% syn and 19% antj by nmr. Interestingly when thi s mixture was treated .under iodine exchanging conditions a 74% y i e l d of .Syji-l,4-diiodoadamantane was observed with no trace of the a n t i isomer by nmr or glc analysis. C j J_j I_K JT\ 1 3 This i s i n spite of the fact that one would expect that the a n t i isomer (diequatorial) would be the more stable and therefore the major product. 34 McKervey has also found that the gem dichloride w i l l rearrange i n the presence of A l C l ^ to y i e l d the syn isomer as the major product. o - 60 -ci A I O 3 ) C H 3 N O 2 + 1 99 However, Yang has found that the syn isomer w i l l slowly rearrange to the a n t i isomer i n the presence of A l C l ^ i n C ^ . C l v H A ' Q 3 ) c s 2 -t-3 8 % conversion Therefore even though the svn isomer appears to be the l e s s stable i t i s the major product i n a l l the above halogen exchange rea c t i o n s . As can be seen from the above discussion the aluminum h a l i d e promoted halogen exchange i s a general r e a c t i o n f o r primary, secondary and t e r t i a r y h a l i d e s . Even very unreactive small r i n g bridgehead h a l i d e s w i l l react by use of a higher b o i l i n g solvent. The procedure i s very mild and proceeds i n high y i e l d s . Aromatic halides are i n e r t to the re a c t i o n conditions. B) Photochemistry of Bridgehead Halides The u l t r a v i o l e t s p e c t r a ^ 1 of a s e r i e s of a l k y l h a l i d e s i n d i c a t e that bromides absorb at around 200 - 220 nm and iodides at 240 - 260 nm with molar 2 e x t i n c t i o n c o e f f i c i e n t s from 2 - 7 x 10 . This absorption i s due to the n — a * t r a n s i t i o n of the halogen atom. Chlorides were found to absorb below 200 nm. Introduction of a second halogen on the same atom was found to move X max to longer wavelengths and increase e by a f a c t o r of 2 - 3. For studies of the synthetic p o s s i b i l i t i e s of photochemical s u b s t i t u t i o n s of halogenated adamantanes i t was desireable to obtain the uv spectra of a - 61 -s e r i e s of adamantyl h a l i d e s . Table V U l t r a v i o l e t Spectra of Adamantyl Halides Compound 1- AdI 2- AdI 1,3-Adl 2 1,3-Adl 2 1,2-Adl 2 syn 1,4-Adl 2 syn 1,4-Adl 2 1-C1, 3-IAd Me 2AdI Me 2AdI 2 1-Ad-Ad-I A d l 3 A d l 3 AdI. 4 2,2-AdBr 2 AdBr. 4 4& -4 M 10 Solvent X max nm e 10 2.48 CH30H 263 1.29 3.34 CH30H 257 1.11 1.69 CH30H 267 2.25 4.38 CH 2C1 2 266 2.47 3.72 CH 2C1 2 267 1.45 1.59 CH30H 260 1.89 2.70 CH 2C1 2 260 1.93 2.16 CH30H 265 1.11 3.38 CH30H 264 1.18 1.41 CH30H 266 2.62 1.15 CH30H 264 2.78 1.30 CH30H 271 3.39 2.88 CH 2C1 2 272 3.58 2.28 CH 2C1 2 280 4.82 7.28 CH30H 240 1.02 0.37 CH3CN 208 4.60 3.46 CH3QH 259 1.71 X From the above table i t may be seen that the £ values are 5 - 1 0 times as large f o r an ordinary a l k y l h a l i d e . Introduction of a d d i t i o n a l iodine atoms moves the \ max to longer wavelengths with an increase i n the e x t i n c t i o n c o e f f i c i e n t . Adamantyl bromides absorb at very low wavelengths, the tetrabromide at 208 nm. 1) Photolysis of Adamantyl Halides i n Alcohol Solvents The i n i t i a l study of the photochemical r e a c t i o n of halides using alcohols as solvents i n d i c a t e d the absorption of l i g h t energy res u l t e d i n a very rapid reaction compared with simple s o l v o l y s i s . A comparison of the thermal and photochemical r e s u l t s i s .shown below. - 62 C H 3 Method Time Conversion hu = 35° 2Jg hours 100% thermal (reflux) 6 hours 35% thermal (reflux) 24 hours 90% o 30% thermal 25 3 weeks The same reaction f o r 1-bromoadamantane was 100% complete a f t e r 8 hours photochemically and only 60% complete a f t e r r e f l u x i n g i n methanol f o r 24 hours. I n i t i a l e x c i t a t i o n of the C-X bond would lead to promotion of an n e l e c t r o n to the a* antibonding o r b i t a l of the halogen atom. This excited h a l i d e could then undergo homolytic cleavage to a r a d i c a l p a i r or h e t e r o l y t i c cleavage to an ion p a i r as shown below: A Hydrogen abstraction by the bridgehead r a d i c a l would y i e l d adamantane while n u c l e o p h i l i c attack by the alcohol solvent on the bridgehead carbenium ion would y i e l d the adamantyl ether. This d u a l i t y of reaction pathways i s exemplified below: - 63 -X = Br 21 79 t = 8 hours X = I 4 96 t = 2h hours The i r r a d i a t i o n of the bromide gave a l a r g e r amount of the product derived from hydrogen atom tr a n s f e r from the solvent (presumably a free r a d i c a l pathway). The iodide gave ex c e l l e n t y i e l d s of the n u c l e o p h i l i c type product (carbenium ion pathway). The i r r a d i a t i o n of 1-iodoadamantane i n alcohols proved to be a rapid general method of producing high y i e l d s of the corresponding alkoxyadamantane. (In a l l cases^.5% of adamantane was observed) The only alcohol t r i e d which did not y i e l d the desired ether was t_ - butanol. In that case the only product i s o l a t e d was 1-adamantanol. Other reports"1""*" have stated the d i f f i c u l t y i n preparing Jt-butoxy-adamantane, presumably due to the f a c i l e l o s s of the _t-butyl cation leading to 1-adamantanol. The i r r a d i a t i o n of 2-iodoadamantane i n methanol also produced the corresponding secondary methyl ether with no trace of the rearranged - 64 -bridgehead ion. Thus the bridge carbenium ion was not s u f f i c i e n t l y long-l i v e d to undergo rearrangement to the t e r t i a r y c a t i o n . The 1,3-adamantyl d i h a l i d e s also underwent r e a c t i o n i n alcohols as shown below: As with the monohalides the d i i o d i d e reacted almost e x c l u s i v e l y v i a a carbenium ion type pathway and the dibromide v i a the free r a d i c a l pathway as w e l l as the c a t i o n i c one. The d i c h l o r i d e y i e l d e d only a reduction product with no trace of any n u c l e o p h i l i c type products at a l l . As the strength of the carbon-halogen bond increases, the amount of reduction products increases as w e l l . 68 Pinhey has observed the reverse trend i n a study of the i r r a d i a t i o n of meta halogen substituted phenols i n a l c o h o l i c s o l u t i o n . The r e s u l t s - 65 -are shown i n the following scheme. H O ROH R " i P r 62 9 0 19 73 82 X = CI = Br = I He at t r i b u t e d the change to the fact that before nu c l e o p h i l i c attack by ROH could occur, the excited state would have to develop appreciable charge separation. I f the carbon halogen bond energy i s high then t h i s charged pathway can compete favourable with homolytic cleavage. However, with the weaker carbon-iodine bond, homolytic cleavage leading to the free r a d i c a l s would predominate y i e l d i n g reduction products. With the adamantyl halides the rate of the reaction to form the ion pair or carbenium ion appears to be faster than the homolytic cleavage. Therefore, with the weak carbon-iodine bond the majority of the reaction i s v i a h e t e r o l y t i c cleavage. The i s o l a t i o n of 1-methoxyadamantane from the i r r a d i a t i o n of 1,3-dibrorao-adamantane at f i r s t suggested the possible intermediary of dehydroadamantane which was then attacked by a molecule of solvent. ±U2_ CH 3QH_^ X X = H ,CH 3 X - 66 -However, monitoring the r e a c t i o n by glc ind i c a t e d than no 103 dehydroadamantane was present . Instead a stepwise r e a c t i o n was occurring, substantiated by the i s o l a t i o n of two brominated intermediates which disappeared upon further i r r a d i a t i o n . X=H,CH3 Workup of the r e a c t i o n before completion allowed the i s o l a t i o n of these two intermediates by column chromatography and preparative g l c . The same two competing reaction pathways were observed f o r the i r r a d i a t i o n of 1,3,5-trihaloadamantanes. t = 24 hours X = Br 19 50 22 t = 6 hours X = I - - 96 The 1,3,5,7-tetrahalides were not examined because of t h e i r extremely low s o l u b i l i t y i n a l c o h o l s . The competition between carbenium ion and free r a d i c a l pathways was also supported by 0^ studies. I r r a d i a t i o n i n the presence of 0 2 (a good r a d i c a l trapping agent) led to the production of bridgehead alcohols In place of products previously formed by hydrogen atom t r a n s f e r from the solvent. - 67 -CH3OH Y = H, X = I Y = H, X = Br Y = CH 3, X = Br l l 4 21 23 96 7 9 77 -> •X ° 2 Y = H, X = I Y = H, X = Br Y = CH 3, X = Br The c a t i o n i c pathway was r e l a t i v e l y unaffected by the 0^, only the free r a d i c a l pathway could be trapped. The intermediate hydroperoxide (X = 00H) would be reduced to the corresponding alcohol upon workup. Kropp has also observed t h i s trapping by 0^ i n the study of the 1-halo-bicyclo [ 2 . 2 . l ] h e p t y l system. However, i n t h i s case more of the c a t i o n i c pathway was a f f e c t e d by the presence of C^. cX 71 + C H -X = Br X = I 55 15 30 72 ° 2 X = Br X = I 30 40 47 19 41 - 68 -The i s o l a t i o n of the reduction product i n the presence of 0^ was suggested to occur v i a n u c l e o p h i l i c attack by solvent on the excited state to form the bridgehead carbanion which l e d to the reduction product. This pathway was found to y i e l d norbornane with 18% D incorporated at the bridgehead. Thus the carbanion was a miner path i n the production of the hydrocarbon. The same i r r a d i a t i o n using CH^OD as solvent was performed using 1-bromoadamantane. I s o l a t i o n of the adamantane produced and study by mass spectrometry ind i c a t e d that only a 3% incorporation of D had taken place. This r e s u l t suggests that with 1-bromoadamantane only a very small amount of the bridgehead carbanion pathway i s involved. This reluctance of forming the bridgehead carbanion of adamantane has been found by other workers as w e l l 1 ^ . Two cases were discovered where the cont r i b u t i o n of the free r a d i c a l pathway was enhanced. I r r a d i a t i o n of e i t h e r 1-iodo or 1-bromoadamantane i n methanol with added NaCN l e d to an increase i n the amount of adamantane formed. This was probably due to increased e l e c t r o n t r a n s f e r by CN . + H 3 x = Br 41 59 X = I 15 85 21 79 4 96 - 69 -The i r r a d i a t i o n of l-brorno-3-chloroadamantane also y i e l d e d a r e l a t i v e l y large amount of free r a d i c a l product. X = Br 42 - 58 X = I - 99 I r r a d i a t i o n of the iodo-chloride produced the chloroether with no trace of 1-chloroadamantane. Since l i t t l e or no r a d i c a l derived products (reduction to adamantane) are found i n the photolysis of mono, d i and t r i i o d i d e s , the reactions occur almost e x c l u s i v e l y v i a the carbenium ion pathway. The norbornyl system studied by K r o p p 7 1 cannot support a p o s i t i v e charge at the bridgeheads as 2c r e a d i l y as the adamantyl system , so that more free r a d i c a l nature i s expected and found here f o r the iodides. To further support t h i s f a c t the i r r a d i a t i o n of the 1,4-diiodide was studied. Further i r r a d i a t i o n y i e l d e d the two ethers with the diether as the major product. The same rea c t i o n was studied i n CH^OD which resu l t e d i n a 17% incorporation of deuterium at the bridgehead of the monoether. Thus with two iodines there i s s t i l l a s i g n i f i c a n t c o n t r i b u t i o n by the carbanion pathway. In the norbornyl system the major path Is s t i l l c a t i o n i c but with more free r a d i c a l c o n t r i b u t i o n than with the adamantyl system. Later studies indicated that the 1-bromoadamantane rea c t i o n could be - 70 -quenched by the use of a Pyrex f i l t e r ; however, 1-iodoadamantane continued to react. The reason f o r t h i s may be seen from the following graph and the fac t that Pyrex stops any l i g h t with a wavelength shorter than 275 nm. Figure II U l t r a v i o l e t Spectra of Bridgehead Adamantyl Iodides U V of B t l d , « l i . . d U r f l d . g 300 380 Wavelength n n The A max f o r the adamantyl bromides i s at very short wavelengths, the value f o r 1,3,5,7-tetrabromoadamantane i s 208 nm. Thus i n using a Pyrex f i l t e r no e x c i t a t i o n of the C-Br bond may occur. However, the iodides absorb above 275 nm so that they continue to react through Pyrex. Since the photochemistry of halides i s divided into two paths ( i o n i c and free r a d i c a l ) at some early stage of r e a c t i o n , a dis c u s s i o n of the various pathways of photoexcitation seems i n order. The photochemical promotion of electrons i s schematically represented i n the following diagram Figure I I I Jablonski Diagram f o r Excited States - 71 -I n i t i a l l y one has a s o l u t i o n of a compound i n i t s ground state which i s being i r r a d i a t e d by u l t r a v i o l e t r a d i a t i o n . Absorption of a photon r e s u l t s i n the e x c i t a t i o n of an ele c t r o n ~via a symmetry-allowed t r a n s i t i o n to the f i r s t s i n g l e t excited state S, . This may be due to a n ~~7~Tr*> TT —> TT*, or n — } a* depending upon the type of chromophore i n the molecule. Once i n S, the excited state may follow three"possible paths. Path b represents fluorescence i . e . a return to the ground state with the release of energy i n the form of u l t r a v i o l e t r a d i a t i o n . Path c i s a r a d i a t i o n l e s s deactivation to the ground s t a t e , the energy appearing i n the form of heat. The t h i r d p o s s i b i l i t y i s known as intersystem crossing (path d) to the upper v i b r a t i o n a l l e v e l s of the f i r s t t r i p l e t excited s t a t e . C o l l i s i o n s with the surroundings reduce the state to i t s lowest v i b r a t i o n a l l e v e l (path f ) . The T(. state also has a r a d i a t i v e d e a c t i v a t i o n to the ground state (phosphorescence) (path h) and a nonradiative pathway (path g). The T, state i s lower i n energy than S, . Since the ele c t r o n i n T,. and the ground state have p a r a l l e l spins they may not occupy the same space at the same time ( P a u l i p r i n c i p l e ) and therefore e l e c t r o n - e l e c t r o n repulsion i s reduced r e l a t i v e to the S| st a t e . D i r e c t e x c i t a t i o n to Tj. i s symmetry forbidden so that once formed i t i s rather long l i v e d compared to Sj which has an allowed deactivation pathway (fluorescence path b). The r a d i a t i o n l e s s pathways c and g are normally quite slow compared to the other p o s s i b l e paths. The r e l a t i v e population of the T| state depends upon the rate of intersystem crossing (path d). S p i n - o r b i t a l coupling i s required to "mix" the S| and T( states to some extent f o r crossing to occur. This coupling i s greatest when one of the electrons involved i n the t r a n s i t i o n i s i n an o r b i t a l close to a heavy atom such as N, 0 or halogen. This enhancement of - l i -the coupling may be both intermolecular and intramolecular i n nature as shown by the two graphs below^^. Figure IV U l t r a v i o l e t Spectra of Anthracene Figure V E f f e c t of E t h y l An increase i n the s i z e of the heavy atom has three e f f e c t s on Sj. and T j . F i r s t a greater population of T| would r e s u l t due to a greater rate of inter-system crossing. Secondly, a greater y i e l d of phosphorescence (path h) r e l a t i v e to fluorescence (path b) should be observed as a consequence of the greater population of Tj., and f i n a l l y the l i f e t i m e of T| should decrease since the fluorescence would be more "allowed" as a r e s u l t of the greater s p i n - o r b i t a l coupling. The t h i r d r e s u l t may be i l l u s t r a t e d by the following table of phosphorescence (T|.) l i f e t i m e s and the rate constants f o r intersystem crossing from Sj. to Tj (solvent i s a mixture of ethanol, iso-pentane and ether) f o r some halogenated naphthalenes. - 73 -Table VI T r i p l e t L i f e t i m e s and the Rate of Intersystem Crossing ... „. 107, . lifetime Csec) 2.5 1.4 2.3 x 10" 1 1.4 x 10" 2 2.3 x 10~ 3 Therefore i t may e a s i l y be seen that an iodine atom promotes very e f f i c i e n t and rapid intersystem crossing with a bromine, c h l o r i n e and f l u o r i n e atom progressively l e s s e f f e c t i v e . The l i f e t i m e s of the Tj states decrease as the s i z e of the halogen increases. However, the l i f e t i m e of the S'j state i s exceedingly short (t = 10 6 to 10 9 sec) so that i n most systems the Tj state has the greatest p r o b a b i l i t y of undergoing chemical r e a c t i o n . With a l l the above disc u s s i o n i n mind the photochemistry of the bridgehead halogen compounds may be examined more c l o s e l y . A p o s s i b l e mechanism f o r the r e a c t i o n would be as follows. The i n i t i a l e x c i t a t i o n of an n e l e c t r o n on the halogen atom would lead to the Sj s t a t e . I n t e r -system crossing as a r e s u l t of the heavy atom e f f e c t would lead to a Tt s t a t e , the population of which would be greatest f o r the iodides r e l a t i v e to bromides and c h l o r i d e s . The intermediary of t r i p l e t states i n the i r r a d i a t i o n of 1-iodo-adamantane was demonstrated by quenching studies with 1,3-pentadiene. A methanol s o l u t i o n of a 20:1 molar r a t i o mixture of 1,3-pentadiene and 1-iodoadamantane was i r r a d i a t e d through pyrex. The time required f o r complete re a c t i o n was 11 hours. In the absence of the 1,3-pentadiene the reaction was complete a f t e r 2^ hours. K S - T 105 o X o X - R F CI Br I 1 x 10 5 x 10" 5 x 10 2 x 10' 3 x 10 10 - 74 -Normally when Tj states are produced they p e r s i s t long enough to undergo phosphorescence or i n t e r and/or intramolecular reac t i o n . However, i n the presence of a molecule which has a t r i p l e t energy l e s s than that of the substrate Tj then energy t r a n s f e r may occur to form the t r i p l e t state of the quencher and return the substrate t r i p l e t to i t s ground s t a t e . The choice of f i l t e r s should be such that only the substrate absorbs energy. Therefore i n the re a c t i o n of 1-iodoadamantane the 1,3-pentadiene quenches the Tf state and slows the re a c t i o n of the adamantyl iodide down. The rea c t i o n does not stop since the concentration of methanol i s much greater than that of the quencher so that eventually a l l of the adamantyl iodide reacts with the solvent to form 1-methoxyadamantane. 1,3-Pentadiene has an E y of 53 kcal/mole so that the E j of 1-iodoadamantane must be above t h i s value. S e n s i t i z a t i o n i s the reverse process of quenching. A molecule which absorbs energy with f a s t intersystem crossing to form a Tj state i s used to t r a n s f e r energy to the Tj state of the substrate. Here only the s e n s i t i z e r should absorb energy so that d i r e c t e x c i t a t i o n of the substrate does not occur. The Tj state of the s e n s i t i z e r should a l s o be of higher energy than the T ( state of the substrate f o r e f f i c i e n t energy t r a n s f e r to take place. S e n s i t i z a t i o n studies were performed on 1-bromoadamantane i n methanol with a 5-6 to 1 r a t i o of s e n s i t i z e r to adamantyl bromide. There was no rea c t i o n a f t e r 24 hours i r r a d i a t i o n through Pyrex with any of the 108 s e n s i t i z e r s used. The compounds and t h e i r E-j- values are shown below - 75 -Table VII T r i p l e t Energies of Various S e n s i t i z e r s S e n s i t i z e r E-j- kcal/mole benzene 80 acetophenone 73 benzophenone 68 fluorene 67 phenanthrene 66 anthracene 60. 1-naphthaldehyde ' 59.5 Rather than adamantyl bromide, the adamantyl iodide would have been a better model to study but unfortunately the molecule continued to react through a l l f i l t e r s t r i e d so that s e n s i t i z a t i o n studies were not p o s s i b l e . Therefore i t could not be c o n c l u s i v e l y established that t r i p l e t states were responsible f o r the reactions of the adamantyl halides i n a l c o h o l i c s o l u t i o n but they were strongly suspected. Promotion of an n e l e c t r o n to the^-* o r b i t a l would r e s u l t i n decreased s t a b i l i t y of the carbon halogen bond. At the wavelength of absorption there i s more than enough energy 109 a v a i l a b l e f o r cleavage of the C-X bond as shown below Table VIII Energy Conversion T a b l e 1 0 5 Table IX Average Carbon-Halogen Bond Strength \ _1 ( E 9 - E l ) A cm kcal/mole eV Bond Bond Energy 2,000 50,000 143.0 6.20 2,500 40,000 114.4 4.96 3,000 33,333 95.3 4.13 3,500 28,571 81.7 3.54 C-F 116 kcal/mole C-Cl 78 C-Br 68 C-I 51 Once In the long l i v e d ( r e l a t i v e to Sj.) T, state bond cleavage could occur to y i e l d e i t h e r an ion p a i r or r a d i c a l p a i r . The decreased r e a c t i v i t y of the adamantyl chlorides and bromides may be explained by the slower rates of intersystem crossing to the T,. states and also the f a c t that the X max f o r these compounds l i e below 200 nm. The major po r t i o n of the energy given o f f by the high pressure mercury lamp i s above 240 nm so that a longer - 76 -time would be required to populate the Tj states of these bridgehead h a l i d e s . Another p o s s i b i l i t y e x i s t s , howeyer, which has not been eliminated. The free r a d i c a l and carbenium ion products may a r i s e from the two d i f f e r e n t excited states. For 1-iodoadamantane the r a t e of formation of Tj may be so f a s t that only a small amount of f r e e r a d i c a l product (derived from rea c t i o n of St ) r e s u l t s . With 1-bromoadamantane the slower rate of i n t e r -system crossing may allow f o r more r a d i c a l products derived from S j . A great deal more work remains to be done to determine the exact mechanism by which these excited states undergo r e a c t i o n . As a r e s u l t of the nearly exclusive formation of carbenium ion type products from the i r r a d i a t i o n of bridgehead iodides other solvents were t r i e d to determine i f other n u c l e o p h i l i c type products could be i s o l a t e d . 2) I r r a d i a t i o n of Bridgehead Halides i n A l k y l N i t r i l e Solvents A photochemical reaction of adamantyl bromides and iodides with n i t r i l e s was discovered by accident during an attempt to photochemically synthesize 1-cyanoadamantane. I r r a d i a t i o n of a s o l u t i o n of 1-iodoadamantane and sodium cyanide i n DMSO y i e l d e d 88% adamantanol and 8% cyanoadamantane (reaction i n the absence of NaCN yi e l d e d 1-adamantanol e x c l u s i v e l y ) . Therefore, CH^CN was t r i e d as another solvent to d i s s o l v e both the iodide and sodium cyanide. I r r a d i a t i o n through quartz f o r 24 hours y i e l d e d a yellow s o l i d which contained a strong carbonyl i n the i n f r a - r e d . The p u r i f i e d compound was shown to be 1-acetamidoadamantane. I t was thought to be formed v i a the following mechanism: - 77 -The i n i t i a l l y formed bridgehead carbenium ion was attacked by a solvent molecule to y i e l d the n i t r i l i u m cation which was r a p i d l y attacked by water to form the observed amide. When c a r e f u l l y dried CH^CN was used, the reaction was found to be very slow and incomplete. The best r e s u l t s were obtained by the ad d i t i o n of 2 drops of water to the a c e t o n i t r i l e s o l u t i o n of the iodide. The reaction of 1-bromoadamantane was found to be very slow r e l a t i v e to the iodide. The reaction was shown to be appli c a b l e to other n i t r i l e s and proceeded i n good y i e l d s . 'I h(7 RCN R R = Me 95% R = nPr 80% R = Me 88% 9 "NCR R = s P r 8 2 % This mild reaction was i n marked contrast to the strongly a c i d i c conditions required f o r the R i t t e r r e a c t i o n 1 1 0 . R = Me 90% R = nPr 82% Good y i e l d s were also found by M i l l e r f o r the aniodic r e a c t i o n of 111 substituted adamantanes CH 3 CN Q NHCCH-X = H X = F X = CI X = Br 90% 89% 65% 91% - 78 -Vincent has also used the aniodic reaction to produce 2-substituted •A 112 amides Y = H 80% Y = Me 85% The above two methods are well known to proceed v i a intermediate carbenium ions so that the photochemical amide formation probably involves them as w e l l . I r r a d i a t i o n of 1,3-diiodoadamantane was found to lead to the formation of the diamide v i a the e a s i l y i s o l a t e d iodo-amide intermediate. No trace of the monoamide was observed. h i? CH 3 CN 1 I n t e r e s t i n g l y the same re a c t i o n worked f o r exo-2-iodonorbornane to produce the corresponding secondary amides. h i ? I RCN O NHCR R = Me, nPr The i r r a d i a t i o n of 1,4-diiodonorbornane l e d to the formation of two products. il R = Me R = nPr 25 40 75 60 - 79 -I r r a d i a t i o n of the p u r i f i e d iodo^amide led to the formation of the bridgehead mono amide with no evidence f o r any of the diamide product. Unlike the adamantyl case the norbornyl iodoamida reacted e x c l u s i v e l y v i a a free r a d i c a l type mechanism to lead to only the reduction product, 3) I r r a d i a t i o n of Bridgehead Halides i n Amine Solvents I t was i n i t i a l l y hoped that due to the tendency of adamantyl iodides to undergo photochemical c a t i o n i c pathways that i r r a d i a t i o n i n various amines would lead to adamantylamines. However, i r r a d i a t i o n i n diethylamine led to a rapid consumption of s t a r t i n g material with the formation of two free r a d i c a l derived products. Repetition of the re a c t i o n with 0^ bubbling through the s o l u t i o n l e d to the formation of 1-adamantanol e x c l u s i v e l y . Thus only a free r a d i c a l pathway e x i s t s f o r the iodide i n diethylamine. When the free r a d i c a l trapping agent 3,5-di-£.-butyl-4-hydroxytoluene was added to the s o l u t i o n the only product i s o l a t e d was adamantane, and the re a c t i o n required 9 hours to go to completion. A s o l u t i o n of adamantyl iodide i n triethylamine y i e l d e d adamantane (88%) plus the HI s a l t of the solvent a f t e r 15 minutes of i r r a d i a t i o n . In the presence of 3,5-di-J^-butyl-4-hydroxytoluene the reac t i o n required 6 hours for completion. The same r e s u l t was observed with p y r r o l i d i n e as - 80 -solvent; the only product was adamantane. This same reductive behaviour has also been observed f o r the i r r a d i a t i o n of halogenated anthracenes with 11 i • 1 1 3 a l k y l amines . In morpholine, however, a 1;1 r a t i o of free r a d i c a l and carbenium ion type product were observed. The bridgehead amine was i d e n t i c a l to that produced by the s o l v o l y s i s of 1-adamantyl iodide i n reluxing morpholine f o r 60 hours. Again, as with the reactions i n alcoho l s , two explanations may be used f o r the experimental r e s u l t s . The free r a d i c a l r e a c t i o n may r e s u l t from the S/ state which i s r a p i d l y trapped by a solvent molecule. On the other hand, i f the bridgehead adamantyl r a d i c a l i s formed from the T| state, s p e c i f i c solvent i n t e r a c t i o n may favour i t s formation r e l a t i v e to when ROH was the solvent and carbenium ion products predominated. The speed of the reaction i n Et^N suggests that trapping of the bridgehead r a d i c a l occurs almost immediately before any s i g n i f i c a n t amount of carbenium ion can be formed. The excited state produced i n morpholine may be more solvated than i n the other a l k y l amines so that both the adamantyl cation and free r a d i c a l are formed. A comparison of the r e l a t i v e rates of r e a c t i o n f o r the following three reactions i s very interesting? - 81 -hi? CH3OH A =32.6 A =7.3 2.5hr E t 3N A<-=24 15min > 9 0 % As the solvent p o l a r i t y increases ( d i e l e c t i c constant =yu-') , the time of the reaction increases as well as the r e l a t i v e amount of carbenium ion type products. This suggests that whatever the excited state i s , that s o l v a t i o n e f f e c t s appear to be important and that the competition between free r a d i c a l and carbenium ion pathways may be c o n t r o l l e d by the choice of solvents. 4) I r r a d i a t i o n of Bridgehead Halides i n Halogenated Solvents In contrast to i o n i c reactions of adamantane, free r a d i c a l s u b s t i t u t i o n occurs at both bridge and bridgehead p o s i t i o n s . Photochemical c h l o r i n a t i o n 53 of adamantane with C l 2 i n various solvents l e d to mixtures of 1 and 2-chloroadamantane. However, a " f a i r degree" of p o l y c h l o r i n a t i o n was found to occur when carbon t e t r a c h l o r i d e was used as the solvent. The complex mixture of products was not separated. With t h i s i n mind comparative photochemical reactions of adamantane i n CH£1 2, CHCl^ and CCl^ were performed (no C l 2 present). A f t e r i r r a d i a t i o n f o r 48 hours the CH 2C1 2 s o l u t i o n showed no r e a c t i o n , the CHCl^ s o l u t i o n consisted of 68% adamantane, 30% 1-chloroadamantane and 2% 2-chloroadamantane. The - 82 -CCl^ solution contained six chlorinated adamantanes plus large amounts of hexachloroethane. Separation of these products proved d i f f i c u l t . To minimize the separation problems, the photochemical chlorihation of a series of mono-substituted adamantanes in CC1. was examined.. Irradiation 4 of 1-chloroadamantane for 48 hours resulted in the complete consumption of the starting material. Glc analysis showed the mixture to consist of hexachloroethane plus 4 chlorinated adamantanes. Elution down a s i l i c a gel column with 30-60 petroleum ether yielded the hexachloroethane. The chlorinated adamantanes were washed from the column with CHCl^ and eluted with petroleum ether down a long alumina column. The crude isomers were purified by preparative glc. Comparison with authentic samples showed the products to be 1,3-dichloroadamantane, anti-1.4-dichloroadamantane, syn-1.4-dichloroadamantane, and 1,3,5-trichloroadamantane in order of elution from the column. There was no evidence for any of the 1,2-dichloride isomer at a l l . Selective abstraction of H* by various agents has been found to be a function of the size of the abstracting species, as shown in Figure VT. The larger the agent the greater the amount of bridgehead radical formed"'"' This i s similar to the effects which inhibit SN2 type solvolysis reactions of 2-adamantyl species (see page 56). - 83 -Figure VI Free Radical Halogenation of Adamantane - rHY Y Br, X = Br CI, X = CI 2.5 1.0 Y 1.9 1.0 Y c c i 3 , X = CI CC1 , X = Br 24.3 1.0 Y 27.0 1.0 Therefore, with a large abstracting agent l i k e »CC1 3 a b s t r a c t i o n of an H» next to a Cl atom w i l l be s t e r i c a l l y very unfavourable so that the abstract i o n occurs at the 3 or 4 p o s i t i o n instead. This mixture of bridgehead and bridge chlorides i s i n marked contrast 58 to the work of B i l l u p s i n which only bridgehead chlorides were i s o l a t e d . However, the strong acid s o l u t i o n may a c t u a l l y be forming bridgehead carbenium ions. The above photochemical re a c t i o n should be an exclusive free r a d i c a l r e a c t i o n . The same photochemical c h l o r i n a t i o n was repeated with 1-fluoro and 1-bromoadamantane. The same four products were observed plus hexachloroethane. 84 C C ! 4 Clv-H I s o l a t i o n of the products was v i a column chromatography and preparative glc as before. The isomers eluted i n the same order as for the case where X = CI and were assigned on the basis of th e i r s i m i l a r nmr spectra. In view of the above res u l t s the same reactions were i"epeated using bromotrichloromethane as the solvent. I r r a d i a t i o n of a solution of adamantane yielded only 1 and 2-bromoadamantane with no trace of any 114 chlorinated products. This i s supported by work of E i c h l e r who found that abstraction of Br* from TrCCl^ by the bridgehead adamantyl r a d i c a l was 29 times faster than abstraction of CI* from CCl^ by the same r a d i c a l . Quite unexpectedly, the i r r a d i a t i o n of 1-substituted adamantanes in, BrCCl^ led to the exclusive formation of bridgehead products. This procedure proved to be a f a c i l e way of synthesizing mixed adamantyl halides as shown below. hi? B r C C I . X - r T C I , 8 r Also of interest was that no hexachloroethane was produced as shown by glc » analysis. The s t e r i c effects for 'CCl^ abstracting H* from 1-substituted - 85 -adamantanes should be the same i n CCl^ and BrCCl^ and yet mixed bridge and bridgehead products are observed i n CCl^ while only bridgehead products are found i n BrCCl^. (At longer r e a c t i o n times i n BrCCl^ secondary products st a r t e d to form as w e l l , as shown by glc.) P l a c i n g a d d i t i o n a l substituents at the other bridgeheads leads to secondary products as w e l l . The reasons f o r the d i f f e r e n c e i n behaviour of CC1, and BrCCl- are not 4 3 c l e a r . The absence of ^2^6 "*"n t* i e ^ r ^ ^ 3 suggests that very e f f i c i e n t H* abstract i o n by 'CCl^ may be taking place and therefore no coupling to form C^Cl^ occurs. The exclusive bridgehead r a d i c a l formation follows from the bulkiness of the trichloromethyl r a d i c a l as seen before. In the case of CCl^ s o l u t i o n the low s e l e c t i v i t y could r e s u l t from CI* being the abstracting agent. Because of i t s small s i z e a b s t r a c t i o n could lead to both bridge and bridgehead r a d i c a l s . The 'CCl^ r a d i c a l s would to a large extent couple to form hexachloroethane. The i r r a d i a t i o n of 1-iodoadamantane i n e i t h e r CC1, or BrCCl_ l e d to 4 3 s u b s t i t u t i o n of the iodine by ch l o r i n e and bromine with traces of d i h a l i d e s . The same type of s u b s t i t u t i o n f o r various substituted aromatic iodides i n CC1.1"'"5 has been observed. - 86 -JU2 C O * ' X = C H 3 O H O C H 3 C 0 2 H O > C 2 C I 6 + O 6 0 - 9 5 % Thus i t may be ascertained f rom the above reactions that the i r r a d i a t i o n of bridgehead halogen compounds leads to the production of both free r a d i c a l and carbenium ion type intermediates. The r e l a t i v e amount of each depends upon the nature of the halogen atom as w e l l as the type of solvent being used f o r the reacti o n . C. Discussion of Spec t r a l Results I) Mass Spectra: This technique proved to be exceedingly valuable i n the a n a l y s i s of various substituted adamantanes. Two papers have appeared i n the l i t e r a t u r e ; 116 the f i r s t a complete study of twenty 1-substituted adamantanes and the second a study of eight 2-substituted adamantanes 1 1^. Bridgehead mono substituted adamantanes were found to fragment v i a two pathways. For most a l k y l groups and halogen atoms l o s s of X* was the preferred fragmentation. However, f o r groups which could s t a b i l i z e a +ve charge the major 38 fragment corresponded to los s of a C^Hg r a d i c a l with formation of a substituted phenyl c a t i o n . X=halogen,R1N02 With the 2-substituted adamantanes the major fragment was due to loss . 39 of HX or X*from the molecular ion The same pattern was observed f o r the amide photoproducts of the two adamantyl iodides. Table X Fragmentation Pattern f o r Adamantyl Amides Q X=NH<bMe X=NH?P r Q X=NHCMe X=NH§P r The same was observed f o r the corresponding norbornyl amides. P-C 4H 9 P-X 81 100 10 65 69 100 P^ P-X P-HX 100 27 49 100 45 35 - 88 -Table XI Fragmentation Pattern of Norbornyl Amides X=NHCMe p + P-C 2H 5 P-HX 100 23 100 100 27 50 35 100 4 44 100 11 X=NHCMe r " " Pr In both the norbornyl and adamantyl the 2-substituted amides underwent fragmentation, l o s i n g HX as a major pathway. The bridgehead isomers preferred to lose an a l k y l r a d i c a l (C^H^* and C2H,.* ) to y i e l d a resonance s t a b i l i z e d carbenium ion. With the 1-substituted adamantanes, when R = Pr the r e s u l t i n g cation from P-C^H^ was not as stable as when R = Me. This decreased s t a b i l i t y of the phenyl substituted cation as the s i z e of R increased was also found i n the mass spectra of various 1-alkoxyadaman-tanes. The loss of OR increased as the s i z e of R increased. Table XII Fragmentation Pattern of 1-Alkoxyadamantanes P * P - C . R Q P - O R 4 y 25 100 8 41 100 22 70 100 92 51 100 41 50 71 100 3 4 100 16 32 100 = CH2CH2OH 16 7 100 = CH 2CH 2OCH 3 11 4 100 - 89 -The same preference for loss of OR as the size of R increased was also found for the 1,3-diethers. Table XIII Fragmentation Pattern of 1,3-Dialkoxyadamantanes R = Me = Et = nPr = iPr = iBu 26 39 45 40 5 P- C4 H9 100 100 100 100 9 P-OR 26 28 74. 81 100 II) Infrared Spectra: Detailed analysis of the infrared spectra of substituted adamantanes 118 has received l i t t l e attention . Its main use in this study was for comparitive purposes; the spectra for monohalides were very similar as were those for cihalldes and so on. The spectra for the halogenated biadamantanes are shown below as examples (run as KBr pellets). Figure 711 Infrared Spectra of 3,3'-Dihalo-1,1'-Biadamantanes WAVELENGTH (MICRONS) 6 7 8 9 10 1.1 12 13 1.4 00 3000 2000 1500 1200 1000 900 600 700 - 91 -The pattern f o r secondary substituted adamantanes i s not so s i m i l a r , but i s s t i l l comparable. This i s shown above f o r the three svn-1.4-dihalo-adamantanes (CCl^ s o l u t i o n ) . Thus an unknown halogenated adamantane could be assigned as d i s u b s t i t u t e d , t r i s u b s t i t u t e d or whatever by comparison with the spectra of known compounds. I l l ) Nuclear Magnetic Resonance a) 'H (Proton) This technique was by f a r the most u s e f u l f o r the a n a l y s i s of d e r i v a t i v e s of adamantane. The assignments are r e a d i l y made from the chemical s h i f t s and integrated i n t e n s i t i e s . Of s p e c i a l importance i n the case of bridgehead compounds i s the absence of strong coupling. Because of the r i g i d character of the adamantane skeleton, there i s no p o s s i b i l i t y of appreciable d i s t o r t i o n of the expected 60° angle between v i c i n a l hydrogen atoms. Where measurable the J values between protons have been found to be 2.6 Hz. A l l protons i n the molecule are strongly dependant upon the nature 19 of the substituents A t y p i c a l example i s shown below f o r 1-bromoadamantane. ( solvent i s C S 2 ) Figure IX Proton NMR Spectrum of 1-Bromoadamantane - 92 -Only three d i f f e r e n t types of protons are present i n the spectrum. There are two types of protons but they generally resonate together so that the £ protons (at 1.73) are s l i g h t l y broader than thep protons (at 2.28) The £, protons being furthest from the substituent u s u a l l y occur c l o s e s t to the value f o r adamantane i t s e l f ( £ = 1.78). The o" protons always are found as a featureless broad band. In many cases some of the resonances may overlap with each other. In these instances switching to an aromatic solvent l i k e benzene causes spectacular s h i f t s of the resonances. This i s shown below f o r 1-methoxy-adamantane i n and CgHg. Figure X Proton NMR Spectra of 1-methoxyadamantane 1 I : , : i 1 1 1,1 1 1 1 t 1 1 1 1 .1 1 i 1 I i 1 1 ±. ! 'Il ' 1 I ' ' I 1 I 1 I ' • 1 1 1 I 3.0 2,0 10 - 93 -In CS^ s o l u t i o n t h e p and Q" protons resonate at e s s e n t i a l l y the same p o s i t i o n . Changing the solvent to benzene causes an u p f i e l d s h i f t i n these p o s i t i o n s . I n t e r e s t i n g l y , i n a l l cases in v e s t i g a t e d here the p carbons (those c l o s e s t to the substituent) are a f f e c t e d the l e a s t ; they undergo the smallest solvent s h i f t . Since studies have shown no evidence f o r a stable 1:1 type complex of substrate and solvent, i t was suggested that the dipole moment of the substrate caused some weak ordering of the solvent which 119 was geometrically but not thermodynamically equivalent to a complex Thus by u t i l i z i n g the two solvents mentioned above the a n a l y s i s of the nmr spectra of bridgehead adamantyl halides i s r e l a t i v e l y straightforward. This i s due to the f a c t that chemical s h i f t s induced by various substituents 19 are remarkably a d d i t i v e . Knowing the magnitudes of these s h i f t s one can accurately estimate the chemical s h i f t s f o r d i , t r i and t e t r a s u b s t i t u t e d adamantanes. The r e s u l t s f o r monosubstituted adamantanes are shown below. The substituent s h i f t s (subs) are the observed chemical s h i f t of the halo compound minus that f o r adamantane. Table XIV Proton and Substituent S h i f t s of 1-Haloadamantanes V . CS„ s o l u t i o n C,H, s o l u t i o n — j i 6—6 CI Br I F CI Br I 1.81 2.08 2.28 2.62 1.83 2.06 2.26 2.50" +.04 +.31 +.51 +.85 +.06 +.29 +.49 +.73 2.18 2.08 2.04 1.92 1.94 1.80 1.70 1.60 +.31 +.21 +.17 +.05 +.07 -.07 -.17 -.27 S 1.62 1.69 1.73 1.88 1.36 1.38 1.40 1.42 -.15 -.08 -.04 +.11 -.41 -.39 -.37 -.35 - 94 -The above substituent s h i f t s are +ve f o r a downfield s h i f t and -ve f o r an u p f i e l d s h i f t (based up £ = 1.77 for the bridge protons of adamantane and 1.87 f o r the bridgehead protons). Using the above substituent s h i f t s together with the a d d i t i v i t y p r i n c i p l e , one may c a l c u l a t e the expected spectrum f o r any d i , t r i or t e t r a h a l i d e . 1,3-dihalides have four d i f f e r e n t types of protons and the r e s u l t s are shown i n the following table compared with the c a l c u l a t e d values. <*>k j2 = 1.77 + .51 + .51 = 2.79 fS = 1.77 + .51 -.04 = 2.24 "fc* = 1.87 + .17 + .17 =2.21 £ = 1.77 - .04 - .04 =1.69 Table XV Experimental and Calculated Proton Chemical S h i f t s of 1,3-Dihaloadamantanes CS„ s o l u t i o n C,H^ s o l u t i o n 2 6 6 y-x F CI Br I F CI Br I obs 1.98 2.36 2.78 3.26 2.04 2.40 2.77 3.20 c a l c . 1.85 2.39 2.79 3.47 1.89 2.45 2.75 3.23 obs 1.80 2.04 2.26 2.60 1.53 1.73 1.93 2.20 c a l c . 1.66 2.00 2.24 2.73 1.42 1.67 1.89 2.15 obs 2.37 2.28 2.26 1.92 1.85 1.63 1.58 1.23 c a l c . 2.49 2.29 2.21 1.97 2.01 1.73 1.53 1.33 obs. 1.50 1.62 1.73 1.92 0.97 1.00 1.10 1.23 c a l c . 1.47 1.61 1.69 1.99 0.95 0.99 1.03 1.07 T r i s u b s t i t u t e d adamantanes have 3 d i f f e r e n t types of protons as shown X f by the spectra f or the t r i i o d i d e ( C S 2 ) . - 95 -Figure XI Proton NMR Spectrum of 1,3,5-Triiodoadamantane o i ; 15 ic| The c a l c u l a t e d and observed r e s u l t s f o r a l l the t r i h a l i d e s are shown i n the following table. Table XVI Experimental and Calculated Proton Chemical S h i f t s of 1,3,5-Trihaloadamantanes CS^ s o l u t i o n CI Br C-H, s o l u t i o n 6 6 CI Br 1.99 2.32 2.74 3.23 1.87 2.08 2.40 2.87 1.70 2.31 2.75 3.58 1.48 1.96 2.38 2.88 1.75 1.95 2.25 2.58 1.30 1.42 1.61 1.93 1.51 1.92 2.17 2.84 1.01 1.32 1.52 1.80 2.47 2.46 2.41 1.97 1.63 1.42 1.40 0.95 2.80 2.50 2.38 2.02 2.08 1.66 1.36 1.06 For the t e t r a h a l i d e s , since a l l the protons are now equivalent, only a s i n g l e l i n e i s observed. - 96 -Table XVII Experimental and Calculated Proton Chemical S h i f t s of 1,3,5,7-tetrahaloadamantanes CS_ s o l u t i o n C-H, s o l u t i o n 2 6 6 F CI Br I F CI Br I obs. 2.04 2.30 2.65 3.18 1.68 1.81 2.13 2.59 c a l c . 1.55 2.23 2.71 3.69 1.07 1.57 2.01 2.53 The same a d d i t i v i t y r e l a t i o n s h i p may be used f o r the dimethyladamantyl halides and halogenated biadamantanes. The r e s u l t s f o r these compounds are not included i n tabular form. As may be seen from Tables XIV to XVII the agreement between the observed and cal c u l a t e d chemical s h i f t s i s quite good f o r the chl o r i d e s (+ .03 ppm i n CS^, + .11 i n C^H^) and bromides (+ .04 ppm i n C S 2 , + .08 i n C^H^). However, the agreement i s not as good f o r the f l u o r i d e s (+ .22 ppm i n CS„, + .27 i n C,H,,) and iodides (+ .20 ppm i n CS„, + .08 i n C,H.). JL — 0 0 —: A — b o The protons d i r e c t l y adjacent to the halogen atoms deviate to the greatest extent. In CS^ the p protons (adjacent to two halogens) of the f l u o r i d e s appear at a lower f i e l d (deshielding e f f e c t ) than expected and the deviation increases as the number of halogen atoms increase (deviation of d i = +.13 ppm, t r i = +.29,tetra = +.49). The p protons of the iodides follow the reverse trend, appearing at a higher f i e l d ( s h i e l d i n g e f f e c t ) than expected (deviation of d i = -.21 ppm, t r i = -.35, t e t r a = -.51). In CS^ the p' protons (adjacent to one halogen atom) of the f l u o r i d e s and iodides follow the same trend as the 3^ protons. For the f l u o r i d e s the deviations are for d i = +.14 ppm, and t r i = +.24; f o r the iodides the deviations f o r d i = -.13 ppm, and t r i = -.26. When the solvent i s changed to benzene the deviations of observed and calculated f o r the J-l and y8'pr°tons of the - 97 -iodides disappear (average deviation = -,C5 ppm) while those of the f l u o r i d e s increase s l i g h t l y (deviation ofp protons of d i = +.15 ppm, t r i = +.39,.tetra = +.61 and deviation of p' protons of d i = +.11 ppm, t r i = +.29). Although the deviations from a d d i t i v i t y i n cal c u l a t e d chemical s h i f t s i n d i c a t e a cooperative e f f e c t of increased number of halogens i n adamantane, pl o t s of observed chemical s h i f t of the p and p' protons i n CS^ and C^Hg . versus the number of halogen atoms are s t i l l e s s e n t i a l l y s t r a i g h t l i n e s (Figures XII and XIII). In both solvents the j? and p' protons of the adamantyl f l u o r i d e s appear at the highest f i e l d and the iodides at the lowest f i e l d . This i s expected from the an i s o t r o p i c e f f e c t s at p carbon 120 atoms . This downfield s h i f t of I > Br > CI ^  F decreases r e g u l a r l y as the number of halogen atoms increase. As may be seen from the s i m i l a r slopes of the l i n e s i n Figure XII and XIII the e f f e c t s of the 4 halogens i n CS^ are the same. Figure XII Observed Chemical S h i f t of theJJ Protons versus Number of Halogen Atoms P protons are adjacent to 2 halogen atoms JS protons are adjacent to 1 halogen atom • B p r o t o n . C S , P ' o l o m C . H j Numb. f o| M n l o g . n , i > N u m b i r of H t l o g t n a - 98 -J I i ib.r of H a i o a e n . N u m b e r of H . l o g , The e f f e c t of the 4 halogens are also the same i n C,R\. The di f f e r e n c e o o between the slopes i n CS^ and CgHg may be ascribed to the weak ordering 119 of the solvent by the solute as proposed by Fort . No evidence f o r a 1:1 complex was found and the authors suggest that the dipole of the solute causes a "cage-like" construction around the adamantyl h a l i d e . Rapid exchange of the solvent molecules involved i n the "cage" with molecules from the bulk of the solvent would give the r e s u l t s of a 1:1 complex on the NMR time scale but would not be thermodynamically equivalent to one. As may be seen from Tables XIV to XVII the solvent s h i f t increases as the number of halogens increase and i s greatest f o r the protons furthest away from the substituent ( ). Also of i n t e r e s t i s the fac t that the s h i f t i s greatest f o r the iodides (as shown f o r the t r i h a l i d e s below). In a l l cases an u p f i e l d s h i f t i s observed. - 99 -Table XVIII Benzene Solvent S h i f t s f o r 1,3,5-trihaloadamantanes Solvent S h i f t s ( C S 2 — ) C6*V X = F CI Br I pp£ 0.12 0.24 0.34 0.35 pSS 0.45 0.53 0.64 0.65 f 0.84 1.04 1.01 1.02 * S h i f t s are i n ppm u p f i e l d from the resonance i n CS 2 s o l u t i o n . Now turning to an examination of the "Jj" protons one notices that the f l u o r i d e s resonate at the lowest f i e l d , i n d i c a t i v e of an inductive order F > CI y Br 7 I. The downfield s h i f t of F r e l a t i v e to I i s the reverse of 121 the order observed f o r the )f protons of n-propyl halides and various 122 halogenated s t e r o i d a l systems . I t has been suggested that t h i s r e v e r s a l of order f o r the V protons of the 1-adamantyl system was due to the 119 73 overlap of the rear lobes of the bridgehead bonding o r b i t a l s ' . This concept of near lobe overlap has also been suggested to account f o r the same downfield trend from Br to F i n a halogenated cholestane system. This back lobe i n t e r a c t i o n w i l l be examined l a t e r i n the thesis i n an examination 13 19 of the C and F nmr of these bridgehead h a l i d e s . As may be seen from Tables XV and XVI the agreement between ca l c u l a t e d and observed chemical s h i f t s of the V protons i s good f o r the bromides (+ .04 ppm i n CS 2, + .04 i n C ^ ) and iodides (+ .05 ppm i n CS 2. + .10 i n CgHg). The agreement i s not as good f o r the f l u o r i d e s (+ .23 ppm i n CS 2 > + .31 i n C 6K 6) and chlorides (+ .02 ppm i n CS 2, + .17 i n C ^ ) . The d i r e c t i o n of the deviation f o r the "cT*protons of the f l u o r i d e s i s opposite to that for the jS and ^ ' protons (see p a g e * ^ ) . The protons of the f l u o r i d e s appear at a higher f i e l d than expected from the a d d i t i v i t y r e l a t i o n s h i p . A p l o t of the chemical s h i f t of the V protons versus the number of halogen - 100 -atoms produces a s t r a i g h t l i n e as shown i n Figure XIV. Figure XIV Observed Chemical S h i f t of the y Protons versus Number of Halogen Atoms N u m b e r o l H a l o g . n t ' • ^ N u m b e r of H a l o g e n s I f the i n t e r a c t i o n of the back lobes of the bridgehead bonding o r b i t a l s i s important, then pla c i n g halogen atoms i n place of hydrogen should r e s u l t i n a reduction of charge density at the remaining bridgehead carbon atoms. The chemical s h i f t of t h i s ^J" hydrogen would therefore move to lower f i e l d , the magnitude of the s h i f t should increase as the number of halogen atoms at the bridgeheads increased and should be greatest when the most electronegative halogen ( f l u o r i n e ) i s present. This i s indeed observed i n CS^ s o l u t i o n as can be seen i n Figure XIV. The e f f e c t s of F, CI, and Br are s i m i l a r while the in t r o d u c t i o n of a d d i t i o n a l I atoms has only a very small e f f e c t . The s i t u a t i o n i s completely d i f f e r e n t i n benzene s o l u t i o n where u p f i e l d s h i f t s are observed with an increase i n the number of halogens. In f a c t the pl o t i n C^H^ i s very s i m i l a r to the C^H^ p l o t s of the yS andJ3 - 101 -hydrogens i n Figures XII and XIII. A po s s i b l e explanation i s that the deshielding e f f e c t s of the halogen atoms i n s o l u t i o n are o f f s e t by the 41 greater s h i e l d i n g e f f e c t s caused by i n t e r a c t i o n of the solute with the benzene solvent molecules as seen on page 99. These i n t e r e s t i n g ^J" e f f e c t s 13 19 w i l l be examined further i n the discussion of the C and F nmr spectra of these molecules. As a furt h e r t e s t of the accuracy of t h i s a d d i t i v i t y r e l a t i o n s h i p f o r bridgehead p o s i t i o n s of adamantane a s e r i e s of mixed halides were studied as shown i n Tables XIX and XX. Table XIX Experimental and Calculated Proton Chemical S h i f t s of 1-Chloro-3-Haloadamantanes Hi CS 2 s o l u t i o n CgHg s o l u t i o n c X: Hi j-x HI H2 H3 H4 H5 HI H2 H3 H4 H5 F obs 2.23* 1.81* 2.01 2.35 1.55 2.24* 1.55* 1.75 1.85 1.00 c a l c . 2.12 1.73 1.93 2.39 1.52 2.12 1.44 1.65 1.87 0.97 Br 2.56 2.26 2.06 2.26 1.67 2.55 1.88 1.74 1.61 1.05 2.59 2.20 2.04 2.25 1.64 2.55 1.87 1.69 1.63 1.01 I 2.88 2.48 2.16 2.16 1.75 2.76 2.08 1.80 1.42 1.13 2,93 2.54 2.19 2.13 1.80 2.79 2.11 1.71 1.53 1.07 * J = 5.5 Hz - 102-Table XX Experimental and Calculated Chemical S h i f t s of l,3-Dihalo-5-Haloadamantanes HI H2 H3 H4 H5 HI H2 H3 H4 H5 X = Br obs 2.68 2.36 a 2.15 2.46 1.67 b 2.44 2.13 1.58 1.47 1.32 Y = F cal c 2.64 2.28 . 2.09 2.52 1.73 2.34 . . 1.95 . 1.48 1.60 1.09 X = I 3.14 3.00 2.50 2.06 2.35 2.82 2.68 1.92 1.10 1.75 Y = Br 3.43 3.26 2.69 2.14 2.60 2.85 2.64 1.87 .1.16. 1.56 X = CI 2.42 2.56 2.02 2.36 2.16 2.12 2.27 1.43 • 1.57 1.57 Y = Br 2.35 2.51 1.96 . .2.46 .2.12 1.99 2.16 1.30 1.56 1.48 X CI 2.39 2.20 a 1.93 2.47 1.80 b 2.12 1.97 a 1.41 1.58 1.26 Y = F 2 .24 2.04 1.85 2.60 1.65 1.94 1.73 1.26 1.80 1.05 X = Br 2.70 2.56 2.18 2.37 2.06 2.42 2.27 1.59 1.45 1.45 Y = CI 2.71 2.55 2.16 2.42 2.00 2.36 2.18 1.50 1.43 1.32 a) J = • 5.5 Hz b) J = 3.5 Hz As may be seen from the tables deviations again occur but are smaller o v e r a l l than when only one type of halogen i s present. The deviation f o r f l u o r i d e s i n CS„ i s + .09 ppm, + .14 i n C,H,; f o r iodides i n CS~ + .13 ppm and z — — b o Z — + .06 i n CgHgj and f o r chlorobromides i n CS^ + .04 ppm and + .06 i n C^H^. As before the deviations of iodides i n CS^ disappear i n benzene s o l u t i o n while the deviations of the f l u o r i d e s are present i n both solvent systems. Therefore, as may be seen from the above dis c u s s i o n , the proton nmr of bridgehead substituted adamantanes i s an extremely valuable and simple technique to inve s t i g a t e inductive and aniosotropic e f f e c t s of substituents as well as the possible presence of back lobe i n t e r a c t i o n s i n a well defined - 103 -and r i g i d system. The nmr of 2-substituted adamantanes are more complicated than the bridgehead isomers as a r e s u l t of lower symmetry making complete analysis d i f f i c u l t . The spectrum of 2-bromoadamantane i s shown below (CCl^ s o l u t i o n ) . Figure XV Proton NMR Spectrum of 2-Bromoadamantane Till •"r-rr-r f : I r ' ' t I I 'r-' rf-i-rrTrT-rrr' ; : I [ i i i I j I ; I T | I I I I [ i i'I I j I I I I | I I ' , , , i | . i i • | • i I i i i i .1 1 i ii i i i i i i |i i i i V~rT r - r v i i n i i i i i i \ - i - t -H^Br Hoc i ' • I ' • : i I 1 i , ...... — ''.I'll >-M-> ' i \ • ' ' ' ' ' ' ' ' 1 1 1 ' 5 . 0 4 . 0 3 . 0 2 . 0 1.0 The proton c< to bromine i s e a s i l y i d e n t i f i e d because of i t s low f i e l d resonance at £=-4.52. The AB system at $ = 2.36 and $=1.58 (J = 12 Hz) belong to the protons V to the bromine atom on the syn side of the molecule. The a x i a l protons e x i s t i n a 1,3 d i a x i a l arrangement with the Br atom and therefore w i l l be more deshielded ($=2.36) than the e q u i t o r i a l p r o t o n s ^ which appear at $=1.58. The other resonances have been assigned but - 104 -123 required double resonance techniques Substituent s h i f t s may be c a l c u l a t e d and pr e d i c t i o n s made f o r 1,2, 1,4 and 2,4-adamantyl isomers but the agreement i s not as good as f o r the . . , . . . 100, 34, 124 bridgehead isomers ' ' In the case of the 1,4 isomers assignment may be made on the basis of the 1,3 d i a x i a l arrangement of the proton and halogen atom as seen above. For syn-1,4-dichloroadamantane the o" a x i a l protons are deshielded-by the a x i a l secondary CI atom. Also the bridgehead atom causes deshielding so that the doublet occurs fur t h e r downfield than f o r 2-bromoadamantane at & = 2.65. Following t h i s reasoning the downfield s h i f t f o r the dibromide and d i i o d i d e should be even greater. This i s indeed observed experimentally, as shown below. Figure XVI Proton NMR Spectra of syn-1,4-dihaloadamantanes X = Ha. Hot CI 2J55 4.11 Br 2.93 4.46 I 3.24 4.82 - 105 -Therefore i t has been seen that proton nmr i s a u s e f u l method by which various halogenated adamantanes may be studied. The a d d i t i v i t y 19 r e l a t i o n s h i p appears to hold f o r other substituents as w e l l . A study of the carbon nmr spectra of these halogenated adamantanes was undertaken to determine i f the a d d i t i v i t y r e l a t i o n s h i p at carbon would be equally u s e f u l . 13 b) C nmr spectra 13 Substituent e f f e c t s have formed a large part of the work on e a r l y C 125 nmr studies , but the c o r r e l a t i o n of chemical s h i f t s with molecular and e l e c t r o n i c c h a r a c t e r i s t i c s has been u n r e l i a b l e when molecules with dynamic geometry are used. The adamantyl system, because of i t s r i g i d and w e l l defined geometry, i s an i d e a l model to study substituent e f f e c t s . A t y p i c a l example i s shown for 1-bromoadamantane. - 106 -Figure XVII Carbon NMR Spectrum of 1-Bromoadamantane With wide band *H decoupling a l l the resonances appear as s i n g l e t s ; the peak heights represent a combination of the number of carbon atoms plus t h e i r type. For example, quaternary carbons attached to bromine give weak absorptions while CH^ carbons give much stronger absorptions. I n i t i a l studies i n t h i s area have d i f f e r e n t i a t e d the V and £ carbons f o r a l l the 126 monohaloadamantanes by means of off-resonance decoupling. 13 From the C chemical s h i f t s of the monohalides, the substituent s h i f t s could be used to c a l c u l a t e the expected carbon chemical s h i f t s f o r the d i , t r i and t e t r a h a l i d e s . 13 Table XXI C Chemical S h i f t s of 1-mono-Haloadamantanes Substituent Carbon Atom and Associated Substituent S h i f t b p y s H 28.4 (0.0) 37.7 (0.0) 28.4 (0.0) 37.7 (0.0) F C 92.4 (64.0) 42.7 (5.0) 31.4 (3.0) 35.9 (-1.8) CI 68.6 (40.2) 47.5 (9.8) 31.3 (2.9) 35.4 (-2.3) Br 66.2 (37.8) 49.3 (11.6) 32.5 (4.1) 35.5 (-2.2) I 50.7 (22.3) 52.3 (14.6) 33.0 (4.6) 35.6 (-2.1) CN d 30.3 (1.9) 40.0 (2.3) 27.2 (-1.2) 35.8 (-1.9) S h i f t s reported i n ppm downfield from tetramethylsilane. uThe substituent s h i f t s i n parentheses i s the chmical s h i f t of the halo compound minus the chemical s h i f t of adamantane. P o s i t i v e s h i f t s correspond to lower f i e l d . ° J C F values are J * = 184 Hz, 3p = 17.8 Hz, = 10.6 Hz and ^ 2 Hz. dCN = 125.1 A sample c a l c u l a t i o n f o r 1,3-diiodoadamantane, using these substituent s h i f t s of the monohalides, i s shown below. S c*. = 28.4 + 22.3 + 4.6 = 55.3 ?' = 37.7 + 14.6 + 14.6 = 66.9 p = 37.7 + 14.6 - 2.1 = 50.2 y = 28.4 + 4.6 + 4.6 = 37.6 g = 37.7 - 2.1 - 2.1 + 33.5 The above substituent s h i f t s d i f f e r s l i g h t l y from those found by e a r l i e r workers but t h i s i s not s u r p r i s i n g as d i f f e r e n t solvent systems were used i n the three c a s e s 1 2 ^ . - 108 -The calculated and observed chemical s h i f t s f o r a l l the d i , t r i and te t r a h a l i d e s are shown i n the following three tables. Table XXII Experimental and Calculated Chemical S h i f t s of 1,3-di-Halo-adamantanes'*' Substituent F b CI Br I 93.4(95.4) 66.9(71.6) 62.0(70.3) 44.8(55.3) P 48.0(47.7) 56.6(57.3) 59.1(60.9) 64.6(66.9) 41.2(40.9) 45.7(45.2) 46.9(47.1) 49.9(50.2) Calculated values i n parentheses. J C F values are J<*, = 188 Hz, J«*.A = 13.3 Hz, J p' and J V = 10.3 Hz. 31.5(34.4) 33.8(34.2) 34.9(36.6) 36.6(37.6) s 34.3(34.1) 33.5(33.1) 33.6(33.3) 33.7(33.5) 19.0 Hz, and Jp = 16.0 Hz Table XXIII Substituent F b CI Br I Experimental and Calculated Chemical S h i f t s of l,3,5-Trihaloadamantanes a' 92.4(98.4) 64.5(74.4) 58.1(74.4) 39.3(59.9) 46.9(45.9) 54.4(55.0) 56.8(58.7) 61.7(64.8) P 39.9(39.1) 43.8(42.9) 44.8(44.9) 47.4(48.0) Calculated values i n parentheses. 3 J c p values are J « x , = 191 Hz, J«* A= 14.8 Hz, Jp' = 18.8 Hz, Jp= 16.9 Hz and Jt= 12.0 Hz. - 109 -Table XXIV Experimental and Calculated Chemical S h i f t s of 1,3,5,7-tetra-Haloadamantanes*** Substituent . F b 90.4 (101.4) 46.2 (44.1) CI 62.3 ( 77.3) 52.8 (52.7) Br 54.2 ( 78.5) 54.9 (56.5) I 31.1 ( 64.5) 59.7 (62.7) St. Calculated values i n parentheses. b J C F values are J e * . . = 192 Hz, 3<<x = 17.2 Hz, and 3p' = 19.4 Hz. As may be seen from the tables XXII to XXIV, the observed chemical s h i f t s f o r the secondary carbon atoms (^ 3 and p' ) agree q u i t e w e l l to those c a l c u l a t e d using the a d d i t i v i t y r e l a t i o n s h i p while the bridgehead carbons (e< and to" ) resonate at a higher f i e l d than expected. This i s shown i n the following t a b l e . Table XXV Average Deviation of Observed from Calculated Chemical S h i f t s f o r D i , T r i and Tetrahalides Carbons F c i Br I -6.3 -9.9 -16.3 -21.5 +1.3 +0.5 -1.8 - 2.8 +0.5 +0.7 +0.2 + 0.5 r -6.1 -2.0 -3.0 - 1-.9 Good agreement i s observed f o r the secondary carbon atoms adjacent to one halogen atom (p) with l a r g e r deviations f o r the p' carbons. The bridgehead carbons, however, a l l experience large u p f i e l d s h i f t s r e l a t i v e to the s h i f t s - 110 -expected from additivity. Linear relationships were observed i n plots of the chemical shifts of the p and J3 carbon atoms versus the number of halogen atoms as seen in the following figure. Figure XVTII Chemical Shift of p> and J3 Carbons versus Number of Halogen Atoms CO I— E p 70-| 65 6 0 E 55-J Q. QL S 50H si CO " a o 45H O p B p Iodides Bromides Chlorides Fluorides Chlcrides Flucrides CL) H V j x: O 35-0 1 2 3 Number of Halogens, n in C,H,„ X ^ . 10 I6-n n 4 Downfield shift s in the order I ~? Br 7 CI F are observed for the and p,' carbons and this shift decreases regularly as the number of halogens 127 increases. This is expected from the anisotropic effects at J3 carbons 12 5b and has been observed in other systems . This shielding effect increases as the number of halogens is increased, moving the resonances to higher f i e l d . As can be seen from the similar slopes the effect is nearly the same for the four different types of halogen atoms. - I l l -Although the carbon atoms of the halogenated adamantanes deviate to the largest extent ( «< carbon of the t e t r a i o d i d e appears 33.4 ppm u p f i e l d from the value predicted by a d d i t i v i t y ) a p l o t of the chemical s h i f t versus the number of halogen atoms y i e l d s s t r a i g h t l i n e s as shown i n the following graph. Figure XIX Chemical S h i f t of oC Carbons versus Number of Halogen Atoms 10Ch Number of Halogens, n in C H X 10 16-n n The order i s the reverse of that observed with t h ep and JZ carbon atoms i n that an inductive order i s observed i . e . deshielding increases with an increase i n the e l e c t r o n e g a t i v i t y ; F 7 CI ? Br 7 I. However, a d d i t i o n a l halogens do not cause further deshielding; instead, the chemical s h i f t s of the<=< carbons move progressively u p f i e l d . As can be seen from the slopes i n Figure XIX, t h i s s h i e l d i n g e f f e c t i s greatest f o r the iodides. This r e s u l t s i n a 33.4 ppm deviation u p f i e l d f o r the t e t r a i o d i d e from the value c a l c u l a t e d - 112 -from a d d i t i v i t y . These deviations at the <X, p o s i t i o n s of halogenated 1263. adamantanes have also been observed by Pehk et a l who found small u p f i e l d s h i f t s f o r the following two bromides. No explanation f o r these deviations was suggested. of C-Br Deviation from Theory X = COOH -61.2 -2.5 ppm = CH2COOH 60.9 -3.6 ppm The deviations at the ©< p o s i t i o n of the multihalogenated adamantanes are much l a r g e r , the average f o r the twelve compounds i s 13.5 ppm u p f i e l d from that expected by a d d i t i v i t y . In s p i t e of t h i s deviation from a d d i t i v i t y the chemical s h i f t s of the c*.carbons follow a more regular pattern than found f o r the halogenated 128 methanes . The r e s u l t s f o r those compounds are shown below. The f l u o r o -129 methanes have been found to e x h i b i t constantly i n c r e a s i n g deshielding as the number of F atoms i s increased from 1 - 4 . Table XXVI Chemical S h i f t of Various Halogenated Methanes Compound Chemical s h i f t ( CH. 4 - 2.3 CH3C1 25.0 CH 3Br 10.0 CH 3I -20.7 CH 2C1 2 54.0 CH 2Br 2 21.4 C H 2 I 2 -54.0 CHC1 3 77.5 CHBr 3 12.2 CHI 3 -140 CC1. 4 96 CBr. 4 -29 - 113 -Thus as can be seen, the f l u o r i d e s and chlorides exhibit constantly increasing deshielding while iodides show constantly increasing s h i e l d i n g with increased number of halogen atoms. Bromides i n i t i a l l y e x h i b i t deshielding but then begin to show s h i e l d i n g e f f e c t s f o r 3 and 4 bromine atoms. These changes have been ascribed to a combination of s t e r i c , inductive and 128 p o l a r i z a t i o n e f f e c t s . D i r e c t s t e r i c e f f e c t s should be absent i n the bridgehead substituted adamantanes so that the °< carbon chemical s h i f t s could be viewed as inductive deshielding i n the order of F 7 CI 7 Br 7 1 combined with the s h i e l d i n g e f f e c t s due to the p o l a r i z a b i l i t y of the halogen atoms i n the order of I 7 Br 7 CI ~? F. With the o< carbons t h i s p o l a r i z a b i l i t y f a c t o r appears to be the dominant one as the number of halogens increase. The same u p f i e l d s h i f t s i n the order I ~? Br T'Cl are found f o r the o< carbons of the two b i c y c l i c systems shown below. The fS and JB carbons also follow the same order observed f o r the adamantyl system i . e . downfield s h i f t i n the order I 7 Br 7 CI. Table XXVII Carbon Chemical S h i f t s of 1,4-Dihalobicyclo/2.2.l] heptane and £"2.2.2]o ctane X = A 6 X » X = P H 36.5 38.6 29.5 H 23.9 25.8 CI 65.6 54.0 39.8 CI 64.1 37.8 Br 56.4 56.4 41.9 Br 58.9 40.2 I 29.9 61.3 45.7 I 38.9 43.9 The p o l a r i z a b i l i t y e f f e c t s on the <X. carbon atoms of these two b i c y c l i c system are compared with the adamantyl system i n the following table. - 114 -Table XXVIII Carbon and Substituent S h i f t of D i h a l i d e s S 45 X = C l 66.9(38.5) a 64.1(40.2)- 65.6(36.1) Br 62.0(33.6) 58.9(35.0) 56.4(26.9) I 44.8(16.4) 38.9(15.0) 29.9(-6.6) Value i n bracket = chemical s h i f t of carbon of the d i h a l i d e - chemical s h i f t of ex- carbon i n the parent hydrocarbon. The s h i e l d i n g e f f e c t s of the halogen atoms are l a r g e s t f o r the b i c y c l o £"2.2.l]heptyl system with the greatest e f f e c t due to two iodine atoms, the carbon appears 6.6 ppm u p f i e l d from the <=< carbon of the parent hydrocarbon. The unsubstituted bridgehead carbon atoms (y) i n the halogenated adamantanes also deviate, but to a l e s s e r extent than the oC carbons. However, unlike the s t r a i g h t l i n e s found i n Figure XIX, the p l o t of chemical s h i f t of t h e ^ carbon atoms versus the number of halogen atoms i s not l i n e a r as shown below i n f i g u r e XX. As with the J3 and j$ carbons the iodides e x h i b i t the l a r g e s t deshielding; however, unl i k e the other p o s i t i o n s the addition of another halogen atom at an CK carbon r e s u l t s i n a fur t h e r increase of the deshielding of the V carbons. Addition of a t h i r d halogen atom r e s u l t s i n further deshielding of the )f carbon of the t r i i o d i d e and tribromide while s h i e l d i n g i s observed f o r the o" carbon of the t r i c h l o r i d e and t r i f l u o r i d e . E s p e c i a l l y puzzling i s the f a c t that an unsubstituted Qr) bridgehead carbon i s s h i f t e d downfield by an increased number of iodine or bromine atoms at the other bridgeheads while the substituted (»0 bridgehead carbon i t s e l f i s s h i f t e d u p f i e l d by the add i t i o n of iodines or bromines at - 115 -the other bridgehead p o s i t i o n s . Figure XX Chemical S h i f t s of )f Carbons versus the Number c f Halogen Atoms | , , 0 1 2 3 Number of H a l o g e n s , n in C 1QH 1g_ nX f i " P e c u l i a r " influences of the heavier halogen atoms on t h e ^ p o s i t i o n have been noted previously . However, a u n i f i e d basis f o r the chemical s h i f t e f f e c t s at a l l p o s i t i o n s by halogens remains unavailable. A major fa c t o r must involve the i n t e r a c t i o n of the non-bonded 1,3 carbon atoms. This i s supported as presented above, by the good c o r r e l a t i o n of observed and ca l c u l a t e d s h i f t s f o r the J3 and and & carbons f o r a l l of the haloadamantanes but the complete lack of c o r r e l a t i o n f o r the bridgehead and V carbon atoms. 13 These same e f f e c t s are shown by the C nmr spectra of a s e r i e s of mixed 1,3 d i h a l i d e s as shown below. - 116 -Table XXIX Experimental and Calculated Chemical S h i f t s of l-Halo-3-halo-adamantanes Substituent CL. PY s X = F obs. 92.4 66.8 52.2 45.8 40.7 32.5 33.9 Y = CI calc. 95.3 71.6 52.2 45.7 40. H 3V. 3 33.6 X = Br obs. 62.2 66.8 57.8 45.6 46.9 34.2 33.6 Y = CI calc. 69.1 72.7 59.1 45.3 47.0 35.4 33.2 X = I obs. 43.5 66.3 60.6 45.5 49.8 34.7 33.6 Y = CI calc. 53.6 73.2 62.1 45.4 50.0 35.9 33.3 X = F b obs. 92.2 62.0 53.8 47.3 40.9 33.3 34.2 Y = Br calc. 96.5 69.2 54.3 47.5 40.5 35.5 33.7 *" J C F values are J** = 188.5 Hz, JUy = 11.7 Hz, Jp' = 19.5 Hz, Js* = 18.0 Hz, and Jfc- = 9.8 Hz. b J C F values are J . c x = 188.7 Hz, J * y = 10.8 Hz, Ja' = 20.0 Hz, Jpx = 16.8 Hz, and J fc- = 9.6 Hz. Again, excellent agreement i s found for the p , J3' and £ carbons with deviations (average 1.6 ppm) for the V carbons and as large as 10 ppm for the c< carbon atoms. However, i n general the a d d i t i v i t y rule holds quite w e l l and i s very useful i n assigning the chemical s h i f t s observed to the s p e c i f i c carbon atoms. This i s shown i n the following three tables for 1,3-dimethyladamantyl halides and 3,3'-dihalo-1,1'biadamantanes. - 117 -1 Table XXX Experimental and Calculated Chemical S h i f t s of 1,3-Dimethyl-5-haloadamantanes X = CI C2 C3 C4 C5 C6 C7 C8 H obs. 43.8 29.3 36.1 29.3 43.8 30.5 51.7 30.9 c a l c . 43.5 29.0 35.5 29.0 43.0 30.0 50.9 F a obs. 48.4 93.0 40.9 31.5 42.0 34.6 53.0 29.4 c a l c . 48.2 93.0 40.5 32.0 41.4 33.0 49.1 CI obs. 53.4 69.0 45.9 32.0 41.7 34.6 49.6 29.6 c a l c . 53.0 69.2 45.3 31.9 40.9 32.9 48.6 Br obs. 54.9 65.7 47.3 32.5 41.5 53.2 49.4 29.7 c a l c . 54.8 66.8 47.1 33.1 41.0 34.1 48.7 I obs. 58.2 55.9 50.5 33.1 41.7 35.6 49.6 29.5 c a l c . 57.8 51.3 50.1 33.6 41.1 34.6 48.8 CF values are: = = 17.5 Hz; J 2 = 184 Hz; J 3 = 17.5 Hz; = i 9.5 Hz; J 6 - 9.5 Hz. - 118 -Table XXXI Experimental and Calculated Chemical S h i f t s of 1,3-Dimethyl-5,7-Dihaloadamantanes X = CI C2 C3 C4 C5 C6 F a obs. c a l c . 47.6 45.5 93.9 96.0 47.6 46.4 35.5 36.0 49.3 47.3 28.6 CI obs. c a l c . 54.7 55.1 66.5 72.1 51.5 50.7 36.7 35.8 47.9 46.3 28.5 Br obs. c a l c . 57.3 58.7 61.5 70.9 52.8 52.6 38.3 38.2 47.7 46.5 28.7 I obs. c a l c . 62.4 64.7 43.0 55.9 55.6 55.7 39.3 39.2 47.5 46.7 28.6 J C p values J 4 = 10.0 Hz. are = 18.8 Hz; Jo^, • 7 = 186 Hz; J<*-a = 13.1 = 15.6 Hz; Table XXXII Experimental and Calculated Chemical S h i f t s of 3,3'-Dihalo-1,1'-Biadamantanes X = CI C2 C3 C4 C5 C6 C7 H obs. 29.2 35.3 36.6 35.3 29.2 37.6 37.6 sub s h i f t +0.8 -2.4 +8.2 -2.9 +0.8 -0.1 -0.1 F 3 obs. 93.7 41.0 41.6 34.2 31.0 42.3 35.5 c a l c . 93.2 40.3 39.6 33.5 32.2 42.6 35.8 CI 70.0 45.9 41.5 33.7 31.6 47.1 35.1 69.4 45.1 39.5 32.0 32.1 47.4 35.3 Br 67.7 47.6 42.6 33.7 32.6 48.9 35.4 67.0 46.9 40.7 33.1 33.3 49.2 35.4 I 48.6 50.6 43.1 33.6 33.1 52.1 35.4 51.2 49.9 41.2 33.2 33.8 52.2 35.5 J^p values are J l = 183 Hz; J 2 = 17 .0 Hz; J 3 = 9. 6 Hz; J 5 = 1C 0 Hz; J , = 17.0 Hz - 119 -Again, good agreement i s found for a l l the secondary carbon atoms with small deviations f o r the o^and V carbon atoms. As a fur t h e r t e s t of the 13 a d d i t i v i t y r e l a t i o n s h i p , the C spectra of a s e r i e s of 1-alkoxyadamantanes were obtained as shown i n Table XXXIII. With these substituent s h i f t s the expected chemical s h i f t s f o r the diethers could be compared with the experimental values as shown i n Table XXXIV. . Unlike the halogenated adamantanes, no deviations were observed f o r the <=*- carbons, good agreement was found f o r these and thep , ji and £ carbon atoms. However, the i f carbons 12 63 again showed some " p e c u l i a r " s h i e l d i n g e f f e c t causing deviations from 1.8 to 2.5 ppm u p f i e l d . - 120 -Table XXXIII 13 C Chemical S h i f t s of 1-Alkoxyadamantanes Carbon Atom and Associated Substituent S h i f t R = P s Me 3 obs. 72.2 41.0 30.5 36.6 +43.8 +3.0 +2.1 -1.1 E t b 72.2 41.7 30.6 36.6 +43.8 +3.7 +2.2 -1.1 P r C 71.8 41.5 30.6 36.5 +43.4 +3.5 +2.2 -1.2 i P r d 72.4 42.5 30.6 36.5 +44.0 +4.5 +2.2 -1.2 nBu 6 72.3 43.0 30.9 36.8 +43.6 +3.8 +2.4 -0.9 f iBu 72.3 43.0 30.9 36.8 +43.9 +5.0 +2.5 -0.9 nPn S 72.5 41.6 30.7 36.7 +44.1 +3.6 +2.3 -1.0 a) -CH 3 b) -CH 2CH 3 c) -CH 2CH 2CH 3 d) -CH(CH 3) 2 e) -CH 2CH 2CH 2CH 3 f) -CHCH~ N CH 2CH 3 g) -CH 2CH 2CH 2CH 2CH 3 CH 3 = 47.6 CH 2 = 55.0; CH 3 = 16.6 0CH 2 = 61.5; CH 2 = 24.2; CH 3 = 10.8 CH = 61.3; CH 3 = 26.3 0CH 2 = 59.6; CH 2 = 33.0; CH 2 = OCH = 66.8; CH 3 = 23.3; CH 2 = 0CH 2 = 59.7; CH 2 = 28.7; CH 2 = 19.6; CH 3 = 14.0 31.8; CH 2 = 10.7 = 22.8; CH 2 = 22.8; CH 3 - 121 -Table X X X I V Experimental and Calculated Chemical Shifts for 1,3-Dialkoxyadamantanes R = ,8 P Me3 obs. 74.6 44.2 39.8 c a l c . 74.3 43.7 39.6 E t b obs. Ik.2 45.4 40.7 calc. 74.4 45.1 40.3 nPr C obs. 74.1 45.4 40.6 calc. 74.0 44.7 40.0 i P r d obs. 74.7 47.2 41.5 calc. 74.6 46.7 41.0 i B u e obs. 74.7 47.7 41.8 calc. 74.8 47.7 41.8 a) OCH3 0CH 3 = = 63.7 b) OCH 2CH 3 CH 2 = 55.4; CH 3 = 16.4 c) OCH2CH2CH 3 0C%= 61.9; CH 2 = 24.0; CH 3 = d) -OCH(CH3) 2 OCH = 62.0; CH 3 = 25.2 e) -OCHCH x CH^CH OCH = 67.3; CH 3 = 22.9; CH 2 = s 30.8 35.4 32.6 35.5 30.9 35.5 32.8 35.5 30.8 35.5 32.8 35.3 30.9 35.5 32.8 35.3 30.9 35.4 33.4 35.9 As a further test, three unsymmetrically disubstituted adamantanes were examined, the results of which are shown i n Table XXXV. - 122 -Table XXXV Experimental and Calculated Chemical S h i f t s of Unsymmetrical Disubs t i t u t e d Adamantanes -* CI C2 C3 C4 C5 C6 C7 X = Y = F a OEt obs. c a l c . 93.3 94.6 46.9 46.4 74.7 75.2 40.4 39.6 31.3 33.6 41.9 41.6 35.0 34.8 X = Y = B r b OEt obs. c a l c . 63.8 68.4 53.1 53.0 73.9 76.3 40.0 39.2 32.9 34.7 48.2 48.2 34.6 34.4 X = Y = F C CN obs. c a l c . 90.0 91.2 44.6 45.0 34.0 33.3 38.7 38.2 30.3 30.2 41.3 40.8 34.1 34.0 a) J l = OCH2 185.6 Hz = 55.8, , J 2 ~ CH 3 = = 17.0 Hz, 16.2 J 3 " 11.4 Hz, J 5 = 10.2 Hz, J 6 = b) OCH2 = 55.6, CH 3 = 16.2 c) J l = 186.0 Hz , J 2 - 19.4 Hz, J 3 = 10.0 Hz, J 5 = 10.2 Hz, J 6 = CN = 123.4 D Again, i t i s only the bridgehead carbon atoms which experience s i g n i f i c a n t deviations from the cal c u l a t e d values. A comparison of these deviations as a function of the substituent may be seen i n Table XXXVI f o r various substituted h a l i d e s . - 123 -Table XXXVI Deviation from A d d i t i v i t y f o r Bridgehead Carbons of Substituted Adamantyl Halides X = F CI Br I Y = F a -2.0 -4.8 -7.2 u -2.0 -2.9 -4.3 NA -2.9 -1.8 -2.2 Y = CI -2.9 -4.7 -6.9 -10.1 c < y -4.8 -4.7 -5.9 -6.9 -1.8 -0.4 -1.2 - 1.2 Y = Br -4.3 -5.9 -8.3 c ^ y -7.2 -6.9 -8.3 NA V -2.2 -1.2 -1.7 Y = I -6.9 -10.5 NA -10.1 NA -10.5 -1.2 -1.0 Y = 1-Ad +0.5 +0.6 +0.7 -2.6 +2.0 +2.0 +2.1 +2.1 *r -1.2 -0.5 -0.7 -0.7 Y = OEt -1.3 -4.6 -0,5 NA -2.4 NA -2.3 -1.8 Y = CN -1.2 ^ y -0.7 NA NA NA *• +0.1 a) -ve deviations r e f e r to u p f i e l d s h i f t s b) NA = Compound Not A v a i l a b l e Several i n t e r e s t i n g trends may be seen from Table XXXVI. In halogen atoms cause an u p f i e l d deviation at the bridgehead p o s i t i o n s . For the substituted carbons (<>0, the deviation i s l a r g e s t f o r iodine, f o r the - 124 -unsubstituted carbons ('80 f l u o r i n e causes the l a r g e s t d e v i a t i o n . For the halogenated biadamantanes the carbon bearing the halogen atom (oO i s not af f e c t e d to a large extent but oCy experiences a downfield de v i a t i o n which seems to be independent of the nature of the halogen atom. As seen from Table XXXIV, no deviation occurs f o r the o< carbon atoms of the diethers. The d i h a l i d e s experience a large deviation at the o(carbon as seen from Table XXXVI. Replacement of one of the halogen atoms by an ethoxy group also r e s u l t s i n an u p f i e l d d e v i a t i o n of the o^x carbon atom, the magnitude of which i s about 60% of that caused by a halogen atom. The above r e s u l t s provide further support f o r the concept that non-bonded e f f e c t s are important at the 1,3 p o s i t i o n s of the adamantane system. 19 The p o s s i b i l i t y that such i n t e r a c t i o n s would also appear i n the F spectra of these molecules was examined i n the following s e c t i o n . 19 C) F nmr Spectra As a further measure of the influence of substituents on chemical s h i f t s 19 around the adamantane r i n g s t r u c t u r e , the F spectra of a.series of substituted fluoroadamantanes ( i n CCl^) were examined, The r e s u l t s are presented i n Table XXXVII. - 125 -Table XXXVII 1 1 p Chemical S h i f t s of Substituted 1-Fluoroadamantanes Fluorine Atom and Associated Substituent S h i f t Rl R2 R3 Chemical S h i f t 3 Substituent ! H H H -128.0 0.0 H 1-Ad H -127.8 +0.2 H H F -132.5 -4.5 H H CI -133.0 -5.0 H H Br -131.6 -3.6 H H CN -133.9 -5.9 H H OCH 2CH 3 -132.5 -4.5 H H NHCCH_ B 3 -132.2 -4.2 H F F -138.9 -10.9 H CI CI -136.4 -8.4 H Br Br -133.2 -5.2 F F F -148.5 -20.5 H CH 3 CH 3 -132.9 -4.9 F . CH 3 CH 3 -139.8 -11.8 CI CH 3 CH 3 -137.0 -9.0 Br CH 3 CH 3 -135.9 -7.9 s y n -137.2 -9.2 a n t i -132.4 -4.4 a) Chemical s h i f t i n ppm r e l a t i v e to i n t e r n a l CFC1 3 b) Chemical S h i f t of the substituted fluoroadamantane-chemical s h i f t of fluoroadamantane. Negative values i n d i c a t e an u p f i e l d s h i f t . - 126 -In a l l cases (except when R2 = l-adamantyl) an u p f i e l d s h i f t of the 19 F resonance i s observed by the addition of various substituents. This u p f i e l d s h i f t i s inconsistent with theories concerning the e f f e c t of electron-withdrawing substituents on chemical s h i f t s . In the fluoromethanes 19 131 the F resonance i s greatly s h i f t e d to lower f i e l d , consistent with an inductive order, the magnitude of the s h i f t i ncreasing as the number of F atoms i s increased. This downfield s h i f t i s not observed with the adamantyl f l u o r i d e s ; i n f a c t the a d d i t i o n of F atoms r e s u l t s i n the l a r g e s t u p f i e l d s h i f t s r e l a t i v e to 1-fluoroadamantane (see Table XXVII). 132 Dewar and co-workers have proposed that some form of s u b s t i t u e n t -induced s t r u c t u r a l change may be involved with various f l u o r i n a t e d anthracenes; however, these e f f e c t s should be r e l a t i v e l y unimportant f o r the r i g i d adamantyl system. These u p f i e l d s h i f t s have also been found f o r 130 the bicyclo£2.2.2]octyl system as shown below X SCS (Substituent Chemical S h i f t ) F -4.4 p N/" C0 2Et -9.2 These u p f i e l d s h i f t s were also l a r g e l y ascribed to a s t r u c t u r a l change induced by the electron-withdrawing substituent possibly leading to an increase i n the C-F bond order. However, as Table XXXVII i n d i c a t e s , f o r substituted fluoroadamantanes s i g n i f i c a n t u p f i e l d s h i f t s are observed f o r both electronegative and e l e c t r o p o s i t i v e substituents. The l a r g e s t u p f i e l d s h i f t s are due to f l u o r i n e atoms but the e f f e c t i s not r e s t r i c t e d to f l u o r i n e nor s p e c i f i c p o s i t i o n of substituent. Table XXXVII ind i c a t e s that a f l u o r i n e , two bridgehead methyls, ethoxy group, cyano, acetamido, bridgehead c h l o r i n e , aji£i-4-chlorine or two bromine atoms a l l cause a substituent-induced chemical s h i f t of about 5 ppm u p f i e l d . - 127 -133 A study by tfahl has shown that various a l k y l groups also produce an u p f i e l d substituent s h i f t as shown in Table XXXVIII. l -F Table XXXVIII Fluorine and Substituent Chemical S h i f t s of Alkyl-Substituted 1-Fluoroadamantanes Rl R2 R3 Chemical S h i f t Substituent S h i f t H H H -130.0 0.0 H H CH 3 -132.8 -2.8 H CH 3 CH 3 -135.3 -5.3 CH 3 CH3 C H 3 -137.8 -7.8 H H Et -132.3 -2.3 H H i P r -131.2 -1.2 H H t-Bu -130.1 -0.1 This seemingly electron-withdrawing nature of the methyl group i s also supported by s o l v o l y s i s studies of methyl substituted 1-bromoadamantanes. The successive addition of bridgehead methyl groups to 1-bromoadamantane reduces the rate by approximately 30%. The other a l k y l groups show an 134 increase i n rate . However, the a c i d i t i e s of a l k y l substituted adamantane 1 35 carboxylic acids suggest that methyl i s more el e c t r o p o s i t i v e than hydrogen ' Table XXXIX A c i d i t i e s of Substituted 1-Adamantane Carboxylic Acids R pKa H 6.78 " Me 6.88 Et 6.95 OOH IPr 7.02 I t lias been suggested that replacement of hydrogen by methyl (or a l k y l ) •> - „ • 9 may produce a small change in geometry which i s ref l e c t e d by the " F chemical - 128 -s h i f t s and the s o l v o l y s i s r a t i o of adamantyl derivatives. This effect would be less pronounced for the pica values since the reaction s i t e i s further removed from tiie adamantane nucleus. Therefore i t would be better to consider a l k y l groups as being polarizable groups rather than being ele c t r o p o s i t i v e or electronegative r e l a t i v e to hydrogen . This p o l a r i z i n g nature of a l k y l groups may also be seen i n Table XL. Table XL Solvolysis of 4-Substituted l-Bicyclo£2.2. lj Octyl Brosylates 5 -1 Substituent (R) 10 k; sec kR/kH H 11.3 1.0 t-Bu 6.2 0.55 i ? r 4.7 0.43 Et 4.0 0.36 Me 3.4 0.30 C,HC 0.8 0.07 6 5 CN 0.003 0.0002 In the above case a l l a l k y l groups appear to be electron withdrawing r e l a t i v e to hydrogen. However, the authors take t h i s to mean that the difference i s not e n t i r e l y inductive i n nature, rather that replacement of hydrogen causes a change i n the hybr i d i z a t i o n at that bridgehead which s l i g h t l y a l t e r s the geometry of the other bridgehead p o s i t i o n , therefore 136 s t e r i c a l l y a f f e c t i n g the rate of reaction. 13 19 The peculiar upf i e l d s h i f t i n C and F nmr of the bridgehead carbons and fluorine atoms may therefore be a result of small, subtle, and yet s i g n i f i c a n t s t r u c t u r a l changes brought about by changes i n the hybridization of a bridgehead carbon atom at which hydrogen has been replaced by some other - 129 -substituent. CONCLUSIONS I t has been shown that the use of i n s i t u generated aluminum halides leads to a very mild and general method for the interchange of non-aromatic halides in high y i e l d . -The reaction i s thought to proceed via a t i g h t l y held ion pair of the aluminum halide and s t a r t i n g material. Even normally in e r t small ring bridgehead positions w i l l react to produce exchanged products i n good y i e l d . The I r r a d i a t i o n of bridgehead halides i n various solvents has been found to y i e l d products from bridgehead carbenium ion and free r a d i c a l pathways, the r e l a t i v e amount of each dependent upon the type of halide and the solvent used. No evidence for the intermediary of any propellane type compounds was found. The carbon-13 and fluorine-19 nmr spectra of bridgehead halogenated adamantanes have indicated some inner-lobe type i n t e r a c t i o n of the 4 bridgehead carbon atoms, the exact nature of which was not determined. •• SUGGESTIONS FOR ' FURTHER ' STUDY I t would be i n t e r e s t i n g to determine the exact nature of the excited states Involved i n the photochemical reactions of the adamantyl halides. The quantum y i e l d s for the reactions of the iodides and bromides would be useful to determine why the iodides react at a much faster rate than the bromides and chlorides. A f i l t e r to stop the reaction of the iodide could also be used to try various s e n s i t i z e r s to i n i t i a t e the reaction. A second area worthy of examination would be the photochemical bromination reaction in BrCCl^. This reaction could be used to lead to otherwise d i f f i c u l t to synthesize bromides which could react to produce in t e r e s t i n g dehydroadamantanes as shown below. - 130 -F i n a l l y , a t h i r d area would be an attempt to q u a n t i t a t i v e l y explain 13 19 the somewhat puzzling C and F nmr r e s u l t s of the halogenated adamantanes. Some form of t h e o r e t i c a l treatment should be made to t r y and s a t i s f a c t o r i l y explain a l l of the observed r e s u l t s . - 131 -EXPERIMENTAL General: Melting points (uncorrected) were obtained with a Thomas Hoover c a p i l l a r y melting point apparatus using sealed tubes. Infra-red spectra were recorded on a Perkin-Elmer 137 spectrophotometer with 0.493 mm sodium c h l o r i d e s o l u t i o n c e l l s using carbon t e t r a c h l o r i d e as the solvent (unless otherwise stated). Band p o s i t i o n s are reported on the frequency (cm "*") scale and i n t e n s i t i e s as strong ( s ) , medium (m), weak (w), broad (b), shoulder (sh). U l t r a v i o l e t spectra were obtained using a G i l f o r d 240 spectrophotometer. Proton (^H) nuclear magnetic resonance spectra were recorded using a Varian Associates T-60, HA-100 or XL-100 spectrometer. A l l samples were run as 10 - 15% s o l u t i o n s i n carbon d i s u l f i d e , deuterochloroform, carbon t e t r a c h l o r i d e or benzene with the chemical s h i f t s expressed i n parts per m i l l i o n (ppm) r e l a t i v e to i n t e r n a l tetramethylsilane at $ = 0.0. Flu o r i n e 19 ( F) nmr spectra were obtained with a Varian Associates T-60 spectrometer. The samples were run as 10 - 30% solutions i n carbon t e t r a c h l o r i d e and the chemical s h i f t s were expressed i n ppm r e l a t i v e to i n t e r n a l t r i c h l o r o f l u o r o • 13 methane. The carbon ( C) nmr spectra were recorded on a Varian Associates CFT-20 spectrometer i n CDCl^ s o l u t i o n with wide band proton ("*"H) decoupling. Again the chemical s h i f t s were expressed as ppm r e l a t i v e to i n t e r n a l tetramethylsilane at % = 0.0. Low r e s o l u t i o n mass spectra were recorded on an Atl a s CH-4b spectrometer with high r e s o l u t i o n work on an A t l a s AEI-MS-902. The i n t e n s i t i e s of the fragments were reported as percentages of the base peak (100%). Both instruments were operated at 70 ev. - 132 -Gas-liquid p a r t i t i o n chromatography (glpc) was performed on a Perkin-Elmer 900 Gas Chromatograph u t i l i z i n g a flame i o n i z a t i o n detection system with helium as the c a r r i e r gas (Z-60 ml/min.) The column used was a 6' by 0.125" 8% OV-17 on Chromosorb W AW-DMCS 80/100 mesh. Temperature programming was r o u t i n e l y used as exemplified below. 125° (4) '-i£> 250° i . e . the column temperature was maintained at 125° f o r 4 minutes then heating at 16° per minute took place u n t i l a f i n a l temperature of 250° was achieved. Preparative glpc was performed on a Varian aerograph model 90-P using helium as the c a r r i e r gas ( 80 ml/min.). The column used was a 5' x 0.25" 10% Carbowax 20m on Chromosorb W 80/100 mesh. The samples were c o l l e c t e d i n Dry Ice-isopropanol cooled v e s s e l s . M i c r o a n a l y t i c a l r e s u l t s were obtained by Mr. P. Borda of t h i s department. Photochemical reactions were c a r r i e d out i n quartz or pyrex tubes equipped with condenser and a take-off j o i n t f o r sampling. The l i g h t source was a GE UA-3 360 watt high pressure mercury lamp i n a water cooled quartz immersion w e l l . The reaction vessels were suspended approximately 10 cm from the immersion w e l l and the whole system surrounded by aluminum f o i l to minimize l o s s of l i g h t . The solutions were degassed w e l l with L - grade nitrogen f o r 15 minutes before i r r a d i a t i o n or with 0^ gas bubbled through the s o l u t i o n during the r e a c t i o n . Methanol was p u r i f i e d by r e f l u x i n g over magnesium metal followed by - 133 -d i s t i l l a t i o n (bp 63°) and storage i n brown b o t t l e s under N 2. Dimethyl sulf o x i d e was s t i r r e d over molecular sieves (5 A) then d i s t i l l e d at reduced pressure over calcium hydride. A c e t o n i t r i l e was d i s t i l l e d from P20,- t n e n r e d i s t i l l e d over Yi^CO^ (bp 81°) and then stored under N 2 i n dark b o t t l e s . Carbon d i s u l f i d e was s t i r r e d over molecular sieves before use. A l l other solvents were e i t h e r reagent or spectrograde and used without further p u r i f i c a t i o n . Sodium cyanide was washed w e l l with absolute ethanol then dri e d under vacuum at 120° f o r f i v e hours before use. S i m i l a r l y , L i B r , L i l , L i C l O ^ and AgF were a l l dri e d at 140° under vacuum f o r 6 hours before use. Aluminum oxide f o r column chromatography was obtained from McArthur Chemical Co. and had a pH range of 9.5 - 10.0. S i l i c a gel was 60 - 120 mesh and was obtained from BDH. Thin l a y e r chromatography was performed on glass plates coated with 2.0 mm of s i l i c a g e l containing uv - 254 fluorescent i n d i c a t o r from Binkman Instruments. - 134 -1-Bromoadamantane Procedure of Landa was followed. To a 200 ml round bottomed f l a s k equipped with a s t i r r i n g bar, condenser and drying tube containing 20.0 g (147 mmoles) of adamantane (Aldrich) was added 40.0 ml of H^SO^ washed bromine. The s o l u t i o n was allowed to r e f l u x with s t i r r i n g f o r three hours whereupon the evolution of HBr had ceased. The rea c t i o n mixture was cooled to room temperature and poured onto 250 g of i c e and 200 ml of CCl^. S o l i d sodium b i s u l f i t e was added with s t i r r i n g to destroy excess B ^ . The so l u t i o n was added to a separatory funnel and the organic l a y e r washed with aqueous sodium carbonate and then water. A f t e r drying over MgSO^ and N o r i t the s o l u t i o n was evaporated to y i e l d a yellow s o l i d which was eluted with 30 - 60 petroleum ether down an alumina column to y i e l d 30.2 g (95%) of f l u f f y white c r y s t a l s , mp 118° - 119° ( l i t 1 8 119 - 1 2 0 ° ) . IR - 1455(s), 1343(m), 1290(s), 1105(m), 1030(s), 980(m), 955(s), 778(s) NMR (CS 2) - unresolved doublet 2.28, (6H), £ ; broad s i n g l e t 2.04, ( 3 H ) , Y * unresolved doublet 1.73, (6H), £ . 1,3-Dibromoadamantane s Into a 200 ml round bottomed f l a s k equipped with s t i r r i n g bar, condenser and drying tube was placed 10.0 g (73.5 mmole) of adamantane. - 135 -The f l a s k was cooled to 0° and 40.0 ml of H oS0. washed Br„ was added. To 2 4 2 t h i s was cautiously added 120 mg of anhydrous AlBr^ which res u l t e d i n a rapid evolution of HBr. The s o l u t i o n was allwed to warm to room temperature and s t i r r e d f o r 0.5 hours followed by s t i r r i n g at 50° f o r 0.5 hours. The f l a s k was then cooled to 0° once again and 220 mg of anhydrous AlBr^ added. A f t e r the evolution of HBr had ceased the s o l u t i o n was s t i r r e d at room temperature f o r 0.75 hours followed by s t i r r i n g at 50° f o r 0.75 hours. The so l u t i o n was cooled to room temperature and worked up as before to y i e l d a l i g h t yellow s o l i d . Glc showed one main peak (200°) with traces of the mono and tri-bromides ( t = a., 1.2 and 3.5 minutes r e s p e c t i v e l y ) . R e c r y s t a l l i z a t i o n from pentane y i e l d e d 15.3 g (73%) of white c r y s t a l s mp 108 - 109° ( l i t 2 2 b 108 - 109°) IR - 1460(s), 1340(m), 1320(s), 1290(s), 1020(s), 1000(m), 955(m), 700(s) NMR (C 6H 6) - s i n g l e t 2.77, (2H),p ; unresolved doublet 1.93, ( 8 H ) , p £ ; broad s i n g l e t 1.58, (2H), )f • unresolved t r i p l e t 1.10, (2H), 6" . '1,3,5-Tribromoadamantane To a s t i r r e d s o l u t i o n of 10.0 g (73.5 mmole) of adamantane and 40.0 ml of ^SO^ washed bromine i n a 200 ml round bottomed f l a s k equipped with condenser and drying tube at 0° was added 220 mg of anhydrous AlBr^. A f t e r the i n i t i a l evolution of HBr had ceased the raa c t i o n mixture was warmed to room temperature and s t i r r e d f o r two hours. Upon cooling once more to 0° 270 mg of AlBr^ was added and the s o l u t i o n allowed to s t i r at room temperature u n t i l the evolution of HBr had ceased. The s o l u t i o n was then allowed to - 136 -r e f l u x with s t i r r i n g f o r 18 hours. Workup as before yi e l d e d a dark yellow s o l i d which was shown to consist of one major peak by g l c (200° t -8 min.). R e c r y s t a l l i z a t i o n from methanol y i e l d e d 18.4 g (76%) of white c r y s t a l s mp 125 - 126° ( l i t 2 2 b 126 - 127°). IR - 1455(m), 1340(w), 1330(w), 1310(s), 1035(m), 975(m), 715(m) NMR (CS 2) - s i n g l e t 2.74, (6H),£y5£; s i n g l e t 2.25 (IH), )f ; s i n g l e t 2.41, (6H),pSo". 1,3,5,7-Tetrabromoadamantane The same procedure f o r the preparation of the tribromide was followed. A f t e r the 18 hour r e f l u x the s o l u t i o n was cooled to room temperature and transferred to a Carius tube which was then frozen i n l i q u i d nitrogen and sealed under vacuum. The tube was placed i n a metal bomb and heated at 175° f o r s i x days. The tube was frozen i n l i q u i d N 2 again, then opened. Workup as before y i e l d e d a dark brown s o l i d which consisted of 85% t e t r a -bromide and 15% tribromide (OV - 17 200° t = 12.0 and 8.0 min. r e s p e c t i v e l y ) . Three r e c r y s t a l l i z a t i o n s from CCl^ yi e l d e d 12.5 g (37%) of a white s o l i d mp 246 - 248° ( l i t 2 2 b 246 - 248°). IR - 1450(m), 1318(s), 1220(m), 998(m), 855(s) NMR (CS 2) - s i n g l e t 2.65, (12H). - 137 -l-Bromo-3,5-dimethyladamantane Hf To a 200 ml round bottomed f l a s k equipped with condenser and drying tube at 0° was placed 10.0 g (61.0 mmole) of 1,3-dimethyladamantane (Sunoco) and 40.0 ml of H„S0. washed Br„. A f t e r the i n i t i a l evolution of 2 4 2 HBr had ceased the mixture was refluxed i n an o i l bath with s t i r r i n g f o r three hours. Workup as before yi e l d e d a l i g h t yellow l i q u i d which showed . one peak by g l c (125(4) ) 200° t = 6.5 min.). D i s t i l l a t i o n afforded 13.48 g (91%) of a col o u r l e s s o i l , bp 66 - 68° (0.12 mm) ( l i t 1 3 7 67 - 69° (0.03 mm)). IR - 1455(s), 1370(w), 1320(m), 1280(w), 1170(m), 975(m), 935(m), 920(m) 895 (m) NMR (CS 2) - s i n g l e t 0.87, (6H), CH 3; s i n g l e t 1.20 , (2H), HI; s i n g l e t 1.38, (4H), H 2; s i n g l e t 1.95, (4H), H 3; s i n g l e t 2.10, (3H), H 4 + E y  I-, 3-Dlbromo-5,7-dimethyladamantane To a s t i r r e d mixture of 10.0 g (61.0 mmole) of 1,3-dimethyladamantane and 40.0 ml of I^SO^ washed B r 2 i n a 200 ml round bottomed f l a s k equipped with condenser and drying tube at 0° was added 100 mg of anhydrous AlBr.^. A f t e r the evolution of HBr had ceased the mixture was s t i r r e d at room temperature for 0.5 hours then at 50° f o r 0.5 hours. A f t e r cooling to 0° - 138 -Another 100 mg of AlBr^ was added and the solution s t i r r e d at room temperature for 0.75 hours and at 50° for 0.75 hours. Workup as before yielded a l i g h t yellow s o l i d which was r e c r y s t a l l i z e d from hexane to y i e l d 11.0 g (74%) of white c r y s t a l s , mp 114 - 115° ( l i t 1 3 8 115 - 116°). IR - 1455(s), 1378(w), 1355(w), 1340(m), 1318(s), 1238(m), 1180(m), 940(w), 907(m) ' • • ' NMR (CS 2) - singlet 0.93, (6H), -CH3; singlet 1.23, (2H), YL ; singlet 1.93, (8H), H 2; singlet 2.60, (2H), H r  1,1'-Biadamantane The biadamantane was prepared by KenWaldman,a 4th year summer student, i n 1971 by the procedure of R e i n h a r d t 8 3 . mp 288 - 289° ( l i t 8 3 290°) IR (KBr) - 1438(s), 1342(s), 1330(s), 1300(m). 1100(m), 1034(m), 961(m), 813(m) NMR (CS 2) - unresolved doublet 1.64, (12H), f$ ; unresolved doublet 1.73, (12H),*\; broad s i n g l e t 1.94, (6H) , £ . 3,3'-Dibromo-1,1'-biadamantane To a 200 ml round bottomed f l a s k equipped with condenser and drying tube at 0° was added 6.7 g of crude biadamantane. To t h i s was added 40.0 ml of H_S0, washed B r 9 . A f t e r the moderate evolution of HBr had ceased the - 139 -s o l u t i o n was s t i r r e d under r e f l u x f o r three hours. Workup as before y i e l d e d 9.2 g of a yellow s o l i d which was shown by nmr and g l c to contain some of the monomer. Subsequent analysis of the s t a r t i n g material showed i t to contain s u b s t a n t i a l amounts of monobromoadamantane. This was removed by washing the crude s o l i d with methanol. The s o l i d was then r e c r y s t a l l i z e d from CCl^ to y i e l d 5.2 g of a white s o l i d , mp 232 - 234° ( l i t 8 3 236°) IR (KBr) - 1440(s), 1340(s), 1320(s), 1300(s), 1237(s), 1132(m), 1102(m), 1020(s), 982(m), 947(s), 890(w), 815(sb), 762(s), 684(sb) NMR (CS 2) - unresolved doublet 1.58, (12H), + H 5; s i n g l e t 2.10, (4H), H^; s i n g l e t 2.20, (12H), H + H 3. General Procedure f o r Iodirte Exchange Into a 100 ml round bottomed f l a s k equipped with s t i r r i n g bar, condenser and drying tube was placed the desired amount of aluminum f o i l torn i n t o small pieces. To t h i s was added the iodine c r y s t a l s and the contents s t i r r e d at 80° i n an o i l bath u n t i l part of the iodine had vapourized, coating the aluminum f o i l . Next was added the carbon d i s u l f i d e through the top of the condenser r e s u l t i n g i n a dark purple s o l u t i o n . This mixture was s t i r r e d under r e f l u x u n t i l a l i g h t pink colour had replaced the o r i g i n a l purple and most of the aluminum f o i l had been broken up i n t o very small pieces (usually r e q u i r i n g 45 to 60 minutes). The re a c t i o n v e s s e l was then removed and cooled down to e i t h e r room temperature, 0° i n an i c e bath, or -50" i n a Dry Ice-isopropanol bath depending upon the type of h a l i d e being used. The h a l i d e was then added d i r e c t l y and the re a c t i o n quenched by the add i t i o n of aqueous sodium b i s u l f i t e (usually a f t e r 2 minutes). Petroleum ether was added and the layers separated. The organic phase was washed with aqueous sodium carbonate, water and dried over MgSO^. Evaporation of the - 140 -solvent under reduced pressure y i e l d e d the crude iodide which was p u r i f i e d by d i s t i l l a t i o n , column chromatography or r e c r y s t a l l i z a t i o n . General Procedure f o r Bromine Exchange In t h i s case the f r e s h l y torn aluminum f o i l was placed with 2 ml of and then the desired amount of l i q u i d bromine added. This s o l u t i o n was refluxed with s t i r r i n g f o r several minutes and then the r e s t of the solvent was added. The rest of the procedure and workup was i d e n t i c a l to that of the iodine exchange r e a c t i o n . General Procedure f o r Chlorine Exchange Unlike the iodine and bromine exchange reactions, carbon d i s u l f i d e could not be used as a solvent f o r c h l o r i n e exchange. Use of c h l o r i n e gas with f r e s h l y torn aluminum f o i l i n carbon d i s u l f i d e led to a rapid oxidation of the solvent to y i e l d elemental s u l f u r . A s i n g l e run with 1,3-dibromo-adamantane produced the desired 1,3-dichloride i n a 1:10 r a t i o with elemental s u l f u r . Separation of the two products was tedious so that t h i s method was abandoned. Instead, to a mixture of f r e s h l y torn aluminum f o i l i n reagent chloroform at 0° was added ch l o r i n e gas, s a t u r a t i n g the s o l u t i o n . A small c r y s t a l of iodine was added, i n i t i a t i n g an exothermic reaction i n which the aluminum f o i l was broken up i n t o small pieces. The s o l u t i o n was cooled to 0° again and the adamantyl bromide was added with s t i r r i n g . The s o l u t i o n was quenched by the addition of water, the l a y e r s separated and the organic phase washed with aqueous sodium carbonate and water. A f t e r drying,the • solvent was evaporated under reduced pressure to y i e l d the crude c h l o r i d e . Use of CCl^ as the solvent led to the desired chlorine exchange but also produced major amounts of hexachloroethane as w e l l . - 141 -General Procedure f o r Fluorine Exchange Into a three necked f l a s k equipped with condenser, drying tube and s t i r r i n g bar was placed the desired adamantyl bromide with a three to four f o l d excess of f r e s h l y dried s i l v e r f l u o r i d e with 75 ml of spectrograde cyclohexane. The mixture was s t i r r e d under r e f l u x and stopped when g l c indicated that s t a r t i n g material had been consumed. The s o l u t i o n was cooled, f i l t e r e d and evaporated to y i e l d the crude f l u o r i d e which was p u r i f i e d by d i s t i l l a t i o n or column chromatography. 1-Fluoroadamantane To a s o l u t i o n of 4.0 g (18.6 mmole) of 1-bromoadamantane i n 50 ml of reagent cyclohexane was added 5.5 g (43.0 mmole) of anhydrous s i l v e r f l u o r i d e . The mixture was allowed to r e f l u x with s t i r r i n g f o r hH hours. F i l t r a t i o n and evaporation y i e l d e d a l i g h t brown s o l i d which was eluted with 30-60 petroleum ether down an alumina column to y i e l d 2.48 (83%) of f l u f f y white c r y s t a l s , mp 212 - 214° (sub) ( l i t 1 8 210 - 212°) IR - 1455(m), 1350(s), 1318(s), 1295(m), 1180(w), 1110(m), 1070(sb) , 970(s), 920(s), 908(w), 835(sb) NMR (CS 2) - unresolved doublet 1.62, (6H), g ; m u l t i p l e t 1.81, (6H),^3 ; broad s i n g l e t 2.18, (3H), \$ . NMR ( 1 9 F ) - s i n g l e t -128.0 ppm. The d i , t r i and t e t r a f l u o r i d e s were prepared by Dr. K. Bhandari, a post-doctoral fellow i n the spring of 1973. - 142 -1,3-Dif luoroadaitiaatane Mp 3 U 240 - 241° MS - 172(37), 129(77), 115(81), 97(51), 43(100) IR - 2450(m), 1360(m), 1340(s), 1320(m), 1295(m), 1240(w), 1110(s), 1060(s), 1000(s), 945(s), 902(m), 835(sb) NMR (C 6H 6) - t r i p l e t J = 5.5 Hz, 2.04, (2H), J S ; broad singl e t 1.85, (2H) , ; broad doublet, J = 3 Hz, 1.53, (8H),^£ 5 broad s i n g l e t , 0 . 9 7 , (2H), £ . NMR ( 1 9F) - singlet -132.5, SCS - 4.5*. Analysis - c 1 0 \ i i F 2 C H calculated 6 9 . 7 6 8.14 found 69.53 7 . 9 6 * SCS = Substituent Chemical'Shift 1,3,5-Trifluofoadamarttane Mp3" 244 - 245° MS - 190(78), 133(84), 129(64), 115(92), 56(100) IR - 1460(m), 1350(m), 1322(s), 1290(m), 1258(m), 1150(s), 1062(m), 1037(s), 995(s), 952(s), 895(w), 835(sb) - 143 -NMR (CS 2) - broad m u l t i p l e t , J = 3.5 Hz, 2.47, (IH), )f ; broad doublet, J = 3.5 Hz, 1.99, (6H),£/?£; t r i p l e t , J = 2.5 Hz, 1.75, (6H),pS£ . NMR ( 1 9 F ) - s i n g l e t , -138.9, SCS -10.9 Analysis - C 1 0 H 1 3 F 3 C H ca l c u l a t e d 63.16 6.84 found 62.88 6.92 1,3,5,7-tetrafluoroadamantane Mp 252 - 253° MS - 208(11), 152(11), 133(76), 129(25), 128(39), 115(14), 109(14), 56(100) IR - 1460(w), 1450(m), 1325(s), 1250(m), 1060(sb), 1035(sb), 995(w), 972(s), 930(m), 840(sb) NMR (CS 2) - quintet, J =3.5 Hz, 2.04, (12H) NMR ( 1 9 F ) - s i n g l e t , -148.5, SCS -20.5 High Resolution Mass Spec - C 1 0 H 1 2 F 4 ca l c u l a t e d 208.0875 found 208.0865 1,3-Dlmethyl-5-fluoroadamantane To a reluxing s o l u t i o n of 3.0 g (12.4 mmole) of l-bromo-3,5-dimethyl-adamantane i n 50 ml of reagent grade cyclohexane was added 4.0 g (31.0 mmole) of f r e s h l y d r i e d s i l v e r f l u o r i d e . The re a c t i o n was stopped a f t e r 3 hours, - 144 -cooled, f i l t e r e d and evaporated to y i e l d a l i g h t yellow o i l which showed o 32 one peak by glc (75 (4) ) 200, t = 6.8 min.). D i s t i l l a t i o n yielded 1.90 g (84%) of a colourless l i q u i d , bp 34° (0.3mm). MS - 182(18), 167(100), 163(4), 147(9), 125(13), 111(28), 107(18) IR - 1455(s), 1375(w), 1355(m), 1342(w), 1328(m), 1185(m), 1150(w), 1060(w), 1053(w), 1015(s), 970(m), 938(w), 915(w)., 880(ra) NMR (CS 2) - s i n g l e t , 0.88, (6H), -CH3; broad s i n g l e t , 1.11, (2H), E • unresolved doublet, 1.28, (4H), H 2; doublet, J = 5.5 Hz, 1.45, (4H), H 3; broad t r i p l e t , J = 5.5 Hz, 1.64, (2H), H 5; m u l t i p l e t , J = 3 Hz, 2.20, (1H), H 4  NMR ( 1 9F) - s i n g l e t , -132.9, SCS -4.9 Analysis - C 1 2 H 1 9 F C H calculated 79.07 10.50 found 79.07 10.60 l-Ethoxy-3-fluoroadamantane To a solution of 400 mg (1.54 mmole) of l-bromo-3-ethoxy-adamantane i n 20 ml of cyclohexane was added 800 mg (6.36 mmole) of AgF. The solution was s t i r r e d under r e f l u x for 3 hours. After f i l t r a t i o n the solution was evaporated to y i e l d a l i g h t yellow s o l i d . E l u t i o n with 30-60 petroleum ether down an alumina column yielded 250 mg (82%) of a colourless o i l . Sublimation of the o i l at 60° (1 mm) yielded white needles. Mp 33 - 34.5°. MS - 198(60), 153(14), 141(100), 123(27), 113(32), 97(11), 95(8) IR - 1444(m), 1382(w), 1358(w), 1340(m), 1320(w), 1300(w), 1120(sb) 1060(s), 998(s), 913(m), 868(w) - 145 -NMR (C 6H 6) - t r i p l e t , J = 7 Hz, 1.11, (3H); s i n g l e t , 1.15, (2H), H 5 >; single t 1.51, (4H), H 3; unresolved t r i p l e t , J = 5.5 Hz, 1.69, (4H), H 2; doublet, J = 5.5 Hz, 1.94, (2H), H^ broad s i n g l e t , 2.02, (2H), H^; quartet, J = 7 Hz, 3.23, (2H) NMR ( 1 9F) - s i n g l e t , -132.5, SCS -4.5 Analysis - c 1 2 H 1 9 F O C H calculated 72.69 9.66 found 71.56 9.54 High Resolution MS calculated 198.2814 found 198.2825 1,3-Difluoro-5,7-dlmethyladamantane To a refluxing solution of 2.0 g (6.2 mmole) of l,3-dibromo-5,7-dimethyladamantane i n 30 ml of reagent cyclohexane was added 5.0 g (39.2 mmole) of freshly dried s i l v e r f l u o r i d e . The reaction was stopped a f t e r 4 hours, cooled, f i l t e r e d and evaporated to y i e l d a yellow o i l which showed one peak by glc (75(4) ) 200 , t = 6.8 min.). D i s t i l l a t i o n yielded 0.87 g (70%) of a colourless o i l , bp 64° (0.7mm). MS - 200(16), 185(100j, 165(5), 129(37), 125(37) IR - 1455(s), 1355(w), 1342(m), 1322(s), 1280(w), 1242(m), 1195(s), 1045(m) 1022(s), 987(s), 928(s), 918(w), 868fm), 675(mb) NMR - (CS 2) - t r i p l e t , J = 5.5 Hz, 1.84, (2H), H 3; unresolved doublet, 1.47, (8H), H 2; broad s i n g l e t , 1.08, (2H), 1^; s i n g l e t , 0.98, (6H), -CH.^ . NMR ( 1 9F) - s i n g l e t , -139.8, SCS -11.8 - 146 -Analysis - C^-H, „F, C H calculated 71.97 9.06 found 71.76 9.20 3,3'-Difluoro-1,1'biadamantane Br AgE H, To a refl u x i n g solution of 2.0 g (4.67 mmole) of 3,3'-dibromo-l,l'-biadamantane i n 40 ml of reagent cyclohexane was added 3.0 g (23.6 mmole) of freshly dried s i l v e r f l u o r i d e . The reaction was cooled to room temperature af t e r four hours, f i l t e r e d and evaporated to y i e l d a l i g h t brown s o l i d . This was eluted with 30-60 petroleum ether down a short alumina column to y i e l d 1.10 g (76%) of f l u f f y white c r y s t a l s , mp 227 - 229°. MS - 306(29), 153(100^ 152(20j, 134(72) IR (KBr) - 1510(s), 1450(m), 1350(w), 1342(w), 1330(w), 1300(w), 1135(w), 1100(w), 1070(m), 1015(m), 965(w), 935(m), 915(mb), 880(w) NMR (CS 2) - unresolved doublet, 1.48, (8H), H 2; broad s i n g l e t , 1.54, (4H), H 5; doublet, J = 5.5 Hz, 1.59, (4H), H^ unresolved doublet, 1.73, (8H), H 3; broad s i n g l e t , 2.24, (4H), H^. NMR ( 1 9F) - s i n g l e t , -127.8, SCS +0.2 Analysis - C 2 0 H 2 g F 2 - _C_ H calculated 78.39 9.21 found 78.49 9.34 - 147 -1-ChlorOadamarttane The catalyst was prepared from 150 mg of' aluminum f o i l with chlorine gas i n 20 ml of chloroform. To t h i s was added 500 mg (2.32 mmole) of 1-bromoadamantane. Workup after 10 minutes yielded a yellow s o l i d which showed one peak by glc (125°(4) ) 200°, t = 5.4 min.). Sublimation yielded 320 mg of a white s o l i d , mp 164 - 165° ( l i t 1 8 164 - 165.5°). IR - 1440(s), 1342(m), 1295(m), llOO(m), 1030(s), 980(w), 955(m), 690(m) 685(mb) NMR (C 6H 6) - unresolved t r i p l e t , 1.38, (6H),£ ; broad singl e t 1.80, (3H), "cf ; broad doublet, 2.06, (6H), f$ . 1,3-Dichlbroadamarttane s The catalyst was prepared as above; from 500 mg of 1,3-dibromo-adamantane (1.7 mmole) a y i e l d of 320 rag (90%) of white crystals (after r e c r y s t a l l i z a t i o n from hexane) was produced, mp 129 - 130 ( l i t 130 - 131 ) MS - 206(5), 204(8), 171(32), 169(100), 133(12), 115(10), 105(5), 91(12) IR - 1445(s), 1360(w), 1340(s), 1320(s), 1295(s), 1158(m), 1110(m), 1040(s), 995(w), 968(s), 955(w), 850(sb), 780(mb) ' NMR (C6R*6) - s i n g l e t , 1.00, (2H), £ ; broad s i n g l e t , 1.63, (2H), V ; s i n g l e t , 1.73, (8H ) ,p£ ; s i n g l e t , 2.40, (2H), p . - 148 -1,3,5-Trichloroadamahtane The catalyst was prepared as before; from 1.0 g (2.68 mmole) of 1,3,5-tribromoadamantane 565 mg (88%) of white cr y s t a l s (from hexane) was produced. Mp 111 - 112° ( l i t 1 3 9 112 - 113°) MS - 240(8), 238(9), 205(66), 203(100), 169(10), 167(12), 133(4), 91(17) IR - 1455(s), 1355(w), 1322(s), 1295(m), 1242(w), 1050(a), 978(m), 865(s), 855(msh) NMR (C 6H 6) - s i n g l e t , 2.08, (6H),£££; s i n g l e t , 1.42, (7H), V 1,3,5,7-TetrachlofOadamaritane The catalyst was prepared as above; from 500 mg (1.1 mmole) of 1,3,5,7-tetrabromoadamantane 260 mg (85%) of white c r y s t a l s (from benzene) was produced. mp 193 - 194° ( l i t 5 2 194°) MS.- 276(11), 274(19), 272(20), 241(33), 239(100), 237(100), 204(26) 202(27), 125(36), 91(50) IR - 1455(s), 1320(s), 1220(s), 992(m), 870(s), 857(wsh) NMR (CS 2) - s i n g l e t , 2.30, (12H) - 149 -l-Chlord-3,5-dimethyladamaritane The catalyst was prepared as above; from 500 mg (2.06 mmole) of l-bromo-3,5-dimethyladamantane 380 mg (90%) of a colourless l i q u i d was produced. bp 60 - 62° (0.8 mm) ( l i t 1 4 0 84 - 86° (4mm)) IR - 1445(s), 1365(w), 1350(w), 1338(w), 1320(m), 1280(w), 1170(mb), 975(w), 938(w), 922(m), 908(m), 895(m), 835(m) NMR (CS 2) - s i n g l e t , 0.89, (6H), -CH3; s i n g l e t , 1.17, (2H), H ; broad doublet, 1.35, (4H), H 2; s i n g l e t , 1.74, (4H), H 3; broad doublet, 1.93, (2H), H 5; broad s i n g l e t , 2.12, (1H), H 4  1.3-Dichloro-5,7-dimethyladamaritane The catalyst was prepared as above; from 750 mg (2.33 mmole) of l,3-dibrorao-5,7-dimethyladamantane 480 mg (88%) of white crystals (from hexane) was produced, mp 95 - 96° ( l i t 7 4 95.5 - 96.5°) MS - 234(1), 232(3), 219(1), 217(3), 199(33), 197(100), 161(13), 141(17), 121(5), 119(9), 91(7) IR - 1458(s), 1377(w), 1350(w), 1340(m), 1320(s), 1238(m), 1176(m), 998(w), 945(m), 938(m), 905(m), 852(s) NMR (CS 2) - s i n g l e t , 0.97, (6H), -CH3; s i n g l e t , 1.15, (2H), H^; s i n g l e t , - 1.70, (8H), H 2; s i n g l e t , 2.24, (2H), H 3 - 150 -3,3'Dichlof6-1,1'-bladamantane 2 The catalyst was prepared from 500 mg of aluminum f o i l i n 30 ml of chloroform, with chlorine gas at 0°. To t h i s was added 1.0 g (2.36 mmole) of 3,3'-dibromo-1,1'-bladamantane. The solution was worked up a f t e r 1 minute to y i e l d a l i g h t yellow s o l i d which was eluted down a short alumina column with pentane to y i e l d 0.67 g (85%) of a white solid.The mass spectrum showed the presence of a bromo - chloro compound i n addition to the desired dichloride. Elution down a larger alumina column with pentane yielded a white s o l i d which was r e c r y s t a l l i z e d from pentane to y i e l d white c r y s t a l s , mp 198.5 - 200°. MS - 340(2), 338(s), 303(1), 177(50), 169(28), 135(50), 134(80), 133(39), 121(43), 119(43), 107(66), 105(62), 91(100) IR (KBr) - I450(m), 1342(m), 1325(m), 1305(m), 1240(w), 1165(w), 1130(w), 1102(w), 1025(s), 985(w), 955(m), 830(s), 810(w), 768(s), 705(s) NMR (CS 2) - unresolved doublet, 1.51, (8H), H 2; s i n g l e t , 1.60, (4H), H 5 ; s i n g l e t , 1.87, (4H), H^; s i n g l e t , 2.00, (8H), H 3, broad s i n g l e t , 2.17, (4H), H 4. High Resolution MS - C 2 C )H 2 3C1 2 calculated 338.1508 found 338.1480 Use of F e r r i c Chloride as an Exchanging Agent The reaction of bridgehead halides with FeCl^ i n CS 2 was found to be rapid on a small scale but increasing amounts of FeCl^ and reaction times were required on a larger scale. In a l l cases the bridgehead halide was - 151 -dissolved i n 20 ml of CS^ and the FeCl-j added to the solution. 1-Haloadamaritaries To a solution of 80 mg of 1-iodoadamantane i n 20 ml of was added 200 mg of FeCTg. The solution turned dark purple immediately and glc showed 1 peak, 1-chloroadamantane. The same reaction was repeated with 50 mg of 1-bromoadamantane and 160 mg of FeCl^. The solution turned dark orange immediately and glc showed 1-chloroadamantane to be the only product. 1^ 3-Dihaloadamaritaries To a solution of 60 mg of 1,3-diiodoadamantane i n 20 ml of CS 2 was added 200 mg of FeCl^. The solution turned dark purple immediately and the corresponding dichloride was the only product by glc. The same reaction was repeated with 40 mg of 1,3-dibromoadamantane and 160 mg of FeCl^. After 1 hour the orange solution consisted of 70% 1,3-dichloroadamantane and 30% l-bromo-3-chloroadamantane. No change i n the ra t i o s occurred over long reaction times. 1,3,5-Trihaldadamahtanes To a solution of 50 mg of 1,3,5-triiodoadamantane i n 20 ml of CS 2 was added 100 mg of FeCl^. The solution turned purple gradually over a period of 1 hour. c i 3 * c i 2 i c n 2 i 3 4 hours - - 1 1 22 hours 2 1 -34 hours only peak - - -The same reaction was repeated with 40 mg of the tribromide and 150 mg of F e C l 3 . C I 3 C l 2 B r C 1 B R 2 B r 3 18 hours - 1 2 3 40 hours - 1.5 2 2 60 hours 2 3 1 - 152 -The same reaction was repeated with 200 mg (.54 mmole) of the tribromide and 840 mg (5 mmoles) of FeCl^ i n 35 ml of refluxing C S 2 . C l 3 C l 2 B r C l B r 2 B r 3 70 min. 2 4 4 1 150 min. 3 3 1 -270 min. 5 1 - -300 min. only product - - -The t r i c h l o r i d e was iso l a t e d i n 82% y i e l d . The F e C l 3 reaction was also performed with l,4-diiodobicyclo£2.2.lJ-heptane. A solution of 170 mg (.5 mmole) of the diiodide with 840 mg (5 mmole) of F e C l 3 was s t i r r e d under re f l u x for 45 hours i n 30 ml of CS,,. The only peak by glc was the corresponding dichloride which was i s o l a t e d i n 75% y i e l d . 1-Iodoadamarttane A l T2 •) C S - > The catalyst was prepared by heating 900 mg (3.5 mmole) of iodine • with 380 mg (14.0 mmole) of aluminum f o i l i n 35 ml of CS 2 for 45 minutes ( o r i g i n a l purple colour had been replaced by a l i g h t . p i n k ) . The solution was cooled to room temperature and 1.0 g (4.7 mmole) of 1-bromoadamantahe was added. The reaction was quenched after 2 minutes by the addition of aqueous sodium b i s u l f i t e , pentane added and the layers separated. The organic phase was washed with aqueous sodium carbonate, water and dried over magnesium sulfate. Evaporation yielded s t i c k y orange cry s t a l s which showed one peak by glc (125(4) 1 0 > 250, t = 8.7 min.) Elu t i o n down a short alumina column with pentane yielded 0.90 (73%) of white c r y s t a l s , mp 74 -75.5° ( l i t 1 8 75 - 76°) - 153 -"MS - 262(trace), 135(84), 107(14), 105(19), 93(58), 92(23), 91(48), 79(100), 77(61) IR - 1460(s), 1348(m), 1290(s), 1105(m), 1028(s), 980(w), 950(m), 670(m) NMR <CS2) - unresolved doublet, 2.62, (6H), |S ; broad s i n g l e t , 1.92, (3H), Y ; unresolved doublet, 1.88, (6H) , 6 . 2-Iodoadamarttane The catalyst was prepared as before from 270 mg (10 mmole) of aluminum f o i l with 850 mg (3.35 mmole) of iodine i n 35 ml of CS 2 < After cooling to 0° i n an ice bath, 1.0 g (4.7 mmole) of 2-bromoadamantane (Aldrich) was added with s t i r r i n g . The reaction was quenched af t e r 2 minutes and worked up as before to y i e l d a l i g h t yellow o i l . (one peak by glc 125(4) 1 6 > 250°, t = 10.1 min.) El u t i o n with 30-60 petroleum ether down a short alumina column yielded 1.14 g (95%) of f l u f f y white c r y s t a l s , mp 47 - 48° ( l i t 2 8 46 - 48°) IR (CS 2) - 1350(w), 1278(s), 1220(m), 1162(s), 1105(s), 1068(w), 1045(m), 1032(w), 988(w), 970(m), 958(w), 908(s), 820(m), 770(w), 720(s) NMR (CS 2) - mu l t i p l e t , 4.84, (IH); m u l t i p l e t s , 1.58 - 2.50, (14H) ~ 154 -B r r 1/ P S The catalyst was prepared as before from 550 mg (20.4 mmole) of aluminum f o i l and 1.3 g (5.1 mmole) of iodine i n 35 ml of C^. After cooling to room temperature, 1.0 g (3.4 mmole) of 1,3-dibromoadamantane was added with s t i r r i n g . The reaction was quenched a f t e r 8 minutes and worked up as before to y i e l d an orange s o l i d which consisted of one peak by glc (200°, t = 11.2 min.) R e c r y s t a l l i z a t i o n from hexane yielded 1.04 g (78%) of white c r y s t a l s , mp 110 - 111° ( l i t 110 - 111°) MS - 388(trace), 261(100), 134(55), 133(40), 127(13), 119(14), 105(27), 91(56), 79(37), 77(35) IR - 1455(s), 1338(m), 1316(s), 1284(s), 1238(m), 1144(w), 1105(w), 1018(s), 990(s), 955(s), 942(w), 785(sb) NMR - s i n g l e t , 3.26, (2H),p ;.unresolved doublet, 2.60, (8H), J3& ; s i n g l e t , 1.92, (4H), f £ . '1,3,5-Triiodoadamaritane The catalyst was prepared as before from 560 mg (20.8 mmole) of aluminum f o i l and 1.3 g (5.2 mmole) of iodine i n 35 ml of CS 2. After cooling to room temperature, 1.0 g (2.68 mmole) of 1,3,5-tribromoadamantane was added. The reaction was quenched after 20 min. and worked up as before pSS Br ppS - 155 -to y i e l d 1.17 g (85%) of l i g h t yellow c r y s t a l s (from benzene), mp 125 - 127°. MS - 516(trace), 387(100), 261(6), 260(8), 133(51), 132(17), 105(17), 91(42), 79(13) IR - 1455(s), 1320(m), 1302(s), 1280(m), 1218(m), 1055(s), 955(m), 685(sb) NMR (CS 2) - s i n g l e t , 3.23, (6H),pp£ ; doublet, J = 3 Hz, 2.58, (6H),p$$ ; m u l t i p l e t , J = 3 Hz, 1.97, (IH), )f . Analysis - ^ Q ^ ^ J _C_ _H_ I calculated 23.37 2.55 74.08 found 23.14 2.58 73.88 1,3,5,7-Tetralodbad.linarttane The c a t a l y s t was prepared as before from 380 mg (14.1 mmole) of aluminum f o i l with 895 mg (3.52 mmole) of iodine i n 35 ml of CS,,. A f t e r cooling to room temperature, 1.0 g (1.56 mmole) of 1,3,5,7-tetrabromoadaman-tane was added. The re a c t i o n was quenched a f t e r 30 minutes and worked up as before to y i e l d 1.22 g (86%) of a l i g h t brown powder i n s o l u b l e i n most solvents. R e c r y s t a l l i z a t i o n from e i t h e r toluene or p y r i d i n e y i e l d e d white needles, mp > 330° ( l i t 5 =370°) MS - 640(trace), 513(trace), 286(96), 285(94), 131(50), 130(39), 129(32), 116(28), 115(36), 91(100) IR (CS 2) - 1420(w), 1310(s), 1200(m), 980(m), 832(s), 705(w), 692(sb) NMR (CS 2) - s i n g l e t , 3.18, (12H) - 156 -1,3-Dimethyl-5-i6d6adamantane Hf The catalyst was prepared as before from 980 mg (3.86 mmole) of iodine and 275 mg (11.8 mmole) of aluminum f o i l i n 30 ml of CS 2. After cooling to room temperature, 1.25 g (5.15 mmole) of l-bromo-3,5 -dimethyladamantane was added with s t i r r i n g . The reaction was quenched after 2 minutes and worked up as before to y i e l d a yellow o i l which consisted of one peak by glc (125(4) — — ) 200°, t = 7.6 min.) D i s t i l l a t i o n yielded a l i g h t pink l i q u i d , 0.92 g (62%), bp 76 - 78° (0.34mm). Glc provided an a n a l y t i c a l sample. MS - 290(trace), 163(100), 107(60), 93(14), 91(14) IR - 1450(s), 1370(w), 1350(w), 1316(m), 1280(m), 1240(m), 1170(s), 970(m), 932(w), 918(m), 890(s), 695(w), 668(m) NMR (CS 2) - doublet, J = 3 Hz, 2.38, (2H), H 5; s i n g l e t , 2.22, (4H), H 3; mult i p l e t , J =3.5 Hz, 1.94, (1H), H 4; doublet, J = 3 Hz, 1.45, (4H), H 2; s i n g l e t , 1.27, (2H), K ; s i n g l e t , 0.84, (6H), -CH3. Analysis - C 1 2 H 1 9 I C H calculated 49.67 6.60 found 49.43 6.79 - 157 -1,3-Diibdc—5,7-dimethyladamantane The catalyst was prepared as before from 310 mg (11.4 mmole) of aluminum f o i l and 860 mg (3.4 mmole) of iodine i n 35 ml of C S 2 . After cooling to 0°, 750 mg (2.28 mmole) of l,3-dibromo-5,7-dimethyladamantane was added with s t i r r i n g . The reaction was stopped after 2 minutes and worked up as before to y i e l d a yellow s o l i d which showed one peak by glc (200(2) 3 2 ) 250°, t = 4.4 min. SM =2.9 min.) Elution with pentane down a short alumina column yielded 820 mg (86%) of white c r y s t a l s mp 101.5 - 102.5° ( l i t 3 0 b 102 - 103°) MS - 289(100), 161(18), 160(15), 119(10), 107(14), 106(12), 105(10), 91(8) IR - 1455(s), 1375(w), 1343(w), 1330(w), 1308(s), 1222(m), 1162(m), 1118(m), 935(w), 920(w), 890(s), 695(s) NMR (CS 2) - s i n g l e t , 3.07, (2H), H 3; s i n g l e t , 2.25, (8H), H 2; s i n g l e t , 1.37, (2H), s i n g l e t , 0.87, (IH), -CH3 3,3'-Dlibdo-1,1'-bladamantane The catalyst was prepared as before from 110 mg (4.0 mmole) of aluminum f o i l and 380 mg (1.5 mmole) of iodine i n 40 ml of CS 2. After cooling to 0°, 428 mg (1.0 mmole) of 3,3'-dibromo-1,1'-bladamantane was added with s t i r r i n g . The reaction was quenched after 2 min. and worked up - 158 -as before to y i e l d a dark brown s o l i d . E lution with pentane down an alumina column yielded 395 mg (76%) of a l i g h t yellow s o l i d . Sublimation and r e c r y s t a l l i z a t i o n from pentane yielded a fine white powder, mp 235 - 237.5° MS - 522(2), 395(31), 268(46), 135(100) IR (KBr) - 1462(w), 1440(m), 1338(m), 1320(m), 1302(m), 1230(m), 1128(w), 1100(m), 1018(s), 980(m), 940(s), 890(w), 805(s), 758(s), 672(s) NMR (CS 2) - unresolved doublet, 1.65, (8H), H 2; mu l t i p l e t , 1.72, (4H), H 5; broad s i n g l e t , 2.01, (4H), H^; s i n g l e t , 2.38, (4H), 1^; unresolved doublet, 2.48, (8H), H 3 High Resolution MS - C 2 0 H 2 8 I 2 calculated 522.2548 found 522.2552 l-IodOadamantane The catalyst was prepared as before from 190 mg (0.75 mmole) of iodine and 100 mg (3.7 mmole) of aluminum f o i l i n 40 ml of.CS 2. After cooling to 0°, 154 mg (1.0 mmole) of the fl u o r i d e was added. The reaction was quenched after 1 minute and worked up to y i e l d an orange s o l i d . Elution with petroleum ether down an alumina column yielded 220 mg (85%) of a white s o l i d i d e n t i c a l i n a l l respects to 1-lodoadamantane. - 159 -1-Chlorbarithracene 141 The procedure of Nonhebel was followed. To a 3 necked 1 l i t r e f l a s k equipped with mechanical s t i r r e r , condenser and drying tube was placed 17.8 g (100 mmole) of anthracene with 27.2 g (202 mmole) of anhydrous CuCl„ and 500 ml of CC1,. The solution was s t i r r e d under r e f l u x for 23 2 4 hours at which time glc showed a 60% reaction. An additional 10.0 g of CUCI2 was added and the solution refluxed for 5 hours. The dark yellow solution was f i l t e r e d and evaporated to y i e l d a dark brown s o l i d . R e c r y s t a l l i z a t i o n from petroleum ether (30-60) yielded 14.7 g (70%) of long yellow needles, mp 103 - 105° ( l i t 1 4 1 104 - 106°) A modified procedure of Friedman was used. A solution of 10.0 g (73 mmoles)of a n t h r a n i l i c acid i n 50 ml of acetone was added dropwise to a refluxing solution of 7.0 g (44 mmoles) of anthracene and 9.3 g (79 mraoles) of i-arayl n i t r i t e i n 100 ml of CH^Cl^. The addition required 2\ hours, at the end of which the solution was washed with 5 x 75 ml of 10% HCI and dried over MgSO^. Evaporation yilded a thick black o i l which was dissolved i n 100 ml of xylene. To t h i s was added 5.0 g of maleic anhydride and the solution was s t i r r e d under reflux for 30 minutes. The cooled solution was - 160 -poured i n 1^0 and C ^ C ^ was added. The organic phase was washed with 5 x 75 ml of 10% KOH and dried over MgSO^. Evaporation of most of the solution yielded a dark o i l which was frozen i n a dry ice/acetone bath and f i l t e r e d to y i e l d a dark brown s o l i d . This s o l i d was placed on a long alumina column and eluted with petroleum ether (30-60). A t o t a l of 3.49 g (32%) of a f l u f f y white s o l i d were isolated by t h i s method, mp 251 - 252° ( l i t 8 9 253 - 254°) NMR (CDC13) - mul t i p l e t s , 7.37, (6H); m u l t i p l e t s , 7.00, (6H); s i n g l e t , 5.42, (2H) 9-Chlorotriptycene CI O — > The same procedure was used as for the preparation of triptycene"^ using 10.0 g (73 mmole)of a n t h r a n i l i c acid, 9.3 g (44 mmole) of 9-chloro-anthracene, and 9.3 g (79 mmole) of _i-amyl n i t r i t e . A f t e r washing with 10% HCI the evaporated s o l i d was dissolved i n 50 ml of xylene and refluxed for 30 min. with 2.0 g of maleic anhydride. Crl^Cl^ was added to the cooled solution and the organic phase washed with 4 x 100 ml of 10% KOH. Evaporation of the dried solution yielded a black o i l which was eluted with petroleum ether (30-60) down an alumina column. The f i r s t few fractions yielded 900 mg (10%) of residual s t a r t i n g material. Further elution with 5% ether-pet ether yielded triptycene plus 9-chlorotriptycene, then f i n a l l y 4.7 g (37%) of a l i g h t yellow s o l i d which was > 95% 9-chlorotriptycene - 161 -by g l c . R e c r y s t a l l i z a t i o n from cyclohexane yielded l i g h t yellow cubes, mp 227 - 229° ( l i t 1 4 2 228 - 229°) NMR (CDC13) - mu l t i p l e t , 7.75, (3H)• m u l t i p l e t , 7.40, (3H) ; multipl e t 7.05, (6H); s i n g l e t , 5.42, (IH) Attempted Exchange of 9-Chlorotriptycene The catalyst for iodine exchange was prepared as before from aluminum f o i l and iodine i n cyclohexane, n-octane, decalin and xylene. The 9-chlorotriptycene was added and the solutions refluxed for 4 days. The reactions i n cyclohexane, octane and xylene showed no change by glc and the 9-chloride was isolat e d in^> 90% y i e l d s . No triptycene could be seen by gl c . The reaction i n decalin showed peaks at shorter retention time than 9-chlorotriptycene or triptycene. Column chromatography on alumina yielded 9-chlorotriptycene plus a small amount of a yellow o i l believed to be a re s u l t of reaction of the solvent since nmr indicated that there were no aromatic hydrogen atoms. 2,2-Dichloroadamantane The procedure of McKervey was followed . To a solution of 5.0 g (33.3 mmole) of adamantanone (Aldrich) i n 10 ml (15.7 g, 115 mmole) of PClg at 0° was added portionwise 9.2 g (43.0 mmole) of PCI,, over a period of 1 hour. The yellow solution was warmed to room temperature and s t i r r e d overnight. The solution was poured into ice water and washed with chloroform. The organic layer was washed with water and dried over MgSO.. - 162 -Evaporation yielded a l i g h t yellow s o l i d which was r e c r y s t a l l i z e d from petroleum ether (30 - 60) to y i e l d 5.80 g (85%) of long colourless needles. Mp 202 - 203° ( l i t 3 4 203 - 204°). MS - 206(6), 204(3), 171(58), 170(53), 169(100), 168(98), 166(23), 133(77) 91(100) IR - 1460(wsh), 1445(s), 1345(m), 1330(w), 1265(m), 1214(w), 1095(m), 1062(w), 1045(w), 1038(m), 958(s), 945(w), 907(s), 843(sb) NMR (CC14) - broad s i n g l e t , 1.84, (8H); s i n g l e t , 2.40, (4H); s i n g l e t , 2.53, (2H) 2,2-Dibromoadamarttane The procedure of McKervey was followed"*1*. To a solution of 2.5 g (16.7 mmole) of adamantanone i n 10 ml of PBr^ at 0° was added i n small portions 7.5 g (17.4 mmole) of PBr^ over a period of 1 hour. The orange solution was worked up the same as for the gem dichloride to y i e l d a dark yellow s o l i d . This was r e c r y s t a l l i z e d from 30-60 petroleum ether to y i e l d 4.2 g (86%) of white needles (darkened on exposure to l i g h t , l i b e r a t i n g HBr gas). Mp 161 - 162° ( l i t 3 4 162 - 163°) MS - no parent, 215(100), 213(100), 150(23), 134(14), 133(55), 91(41) IR - 1470(w), 1448(s), 1343(w), 1300(w), 1260(m), 1208(w), 1092(s), 1060(w) 1037(w), 957(s), 944(w), 898(s) NMR - broad s i n g l e t , 1.93, (8H); s i n g l e t , 2.58, (4H); s i n g l e t , 2.77, (2H) - 163 -Rearrangement of 7,2-Dichlbfbadamaritane The catalyst was prepared as before from 200 mg (7.4 mmole) of aluminum f o i l and 164 ml (3.0 mmole) of bromine i n 40 ml of ref l u x i n g CS2. The solution was cooled to -50° after 1 hour and 410 mg (2.0 mmole) of 2,2-dichloroadamantane was added with s t i r r i n g . The reaction was worked up as before after 1 minute to y i e l d a l i g h t orange s o l i d which consisted . of three peaks i n the r a t i o of 1:2:4 by glc analysis. Preparative glc yielded the pure components. The f i r s t two compounds were shown to be the gem dichloride and gem dibromide by comparison with authentic samples. The major product was found "to be svn-1f4-dibromoadamantane. Mp 108 - 109° ( l i t 3 3 109 - 110°) MS - parent(trace), 215(100), 213(100), 134(7), 133(35), 105(11), 91(19) IR - 1465(w), 1445(m), 1342(m), 1325(w), 1300(w), 1285(m), 1250(m), 1188(w), 1180(w), 1100(m), 1028(w), 1020(s), 975(w), 942(m), 922(m) NMR (CC14) - mu l t i p l e t s , 1.85 - 2.40, (11H); doublet, J = 12 Hz, 2.95, (2H); s i n g l e t , 4.46, (1H) The above reaction was repeated using 4.0 mmole of bromine to prepare the catalyst. The exchange was done at room temperature to y i e l d the syn-1,4-dibromide with only a trace of the gem dibromide. - 164 -Rearrangement of 2,2-DichldfQadamarttane To a solution of 1.0 g (4.88 mmole) of 2,2-dichloroadamantane i n 40 ml of spectrograde CH.JNO2 was added 5.3 g (39.6 mmole) of anhydrous A l C l ^ . The solution was allowed to s t i r for 3 hours at room temperature, then poured into ice water. Carbon tetrachloride was added and the layers separated. The organic phase was washed with water and dried over MgSO^. Evaporation yielded a yellow o i l which was shown to consist of 3 components by glc i n the r e l a t i v e r a t i o of 2:8:1. (100(2) ^ 200 , t = 12.6, 13.2 and 14.7 min.) Elution down an alumina column with petroleum ether (30-60) yielded the three components which were further p u r i f i e d by preparative g l c . The f i r s t component proved to be anti-l.4-dichloroadamantane. Mp 130 - 131° ( l i t 3 3 131.5 - 133.5°) MS - 206(4), 204(8), 171(31), 169(100), 133(14), 113(5), 105(5), 91(16) IR - 1465(wsh), 1445(s), 1360(w), 1340(m), 1335(m), 1280(w), 1220(m), 1100(m), 1025(s), 970(w), 942(m), 922(m) NMR (CCl^) - s i n g l e t , 4.24, (IH); mu l t i p l e t s , 1.20 - 2.20, (13H) The major product was found to be syn-1,4-dichloroadamantane, mp 162 - 163° ( l i t 3 3 157 - 159°) MS - 206(3), 204(5), 171(32), 169(100), 133(18), 113(6), 105(6), 91(17) IR - 1465(wsh), 1440(s), 1340(m), 1330(wsh), 1295(m), 1280(w), 1260(m), 1210(w), 1098(m), 1025(s), 970(w), 943(m), 920(s), 835(s), 777(mb) NMR (CC1A) - broad s i n g l e t , 4.11, (IH); mu l t i p l e t s , 1.30 - 2.70, (11H); - 165 -doublet, J = 12 Hz, 2.65, (2H) The minor product was found to be 1,4,4-trichloroadamantane, mp 153 -154° ( l i t 3 3 152 - 153°) MS - 242(5), 240(6), 238(7), 205(68), 203(100), 170(7), 168(21), 131(21), 125(11), 113(19), 91(23) IR - 1470(wsh), 1433(s), 1342(m), 1282(w), 1180(w), 1098(m), 1065(w), 1040(wsh), 1028(s), 972(m), 944(s), 925(s), 850(s), 835(sb) NMR (CC14) - multiplets, 1.70 - 2.90, (13H) 3 5 Pr6t6adamantari-4-bne o To a solution of 10.1 g (66.5 mmole) of 1-adamantanol i n 200 ml of reagent benzene was added 32.6 g (73.6 mmole) of lead tetraacetate and 18.6 g (73.6 mmole) of iodine. The dark purple solution was s t i r r e d at 70° for 2 hours. The solution was f i l t e r e d into an aqueous sodium b i s u l f i t e solution with s t i r r i n g . The organic phase was then washed with aqueous sodium carbonate, water and dried over MgSO^. Evaporation yielded the 7-iodomethylbicyclo(j3.3.l]nonan-3-one as a dark o i l . IR (crude) - 1715(s) NMR (CC14) - doublet, J = 7 Hz, 2.92, (2H), -CH 2I; m u l t i p l e t , 0.90 -2.40, (13H) The crude o i l was immediately dissolved i n 20 ml of pyridine and s t i r r e d at 70° for lh hours. The purple solution was poured into ice water/ pet ether and the layers separated. The organic layer was washed with aqueous sodium b i s u l f i t e , aqueous sodium carbonate, and water, then dried - 166 -over MgSO^. Evaporation yielded a l i g h t yellow s o l i d which was eluted with petroleum ether (30-60) down an alumina column to y i e l d 5.2 g (52%) of white c r y s t a l s , mp 208 - 209° ( l i t 3 5 210 - 212°) MS - 150(100), 108(18), 107(18), 106(14), 97(56), 80(32), 79(32), 68(15), 67(23), 66(33) IR - 1720(s) NMR (CC14) - broad m u l t i p l e t , 2.67, (2H); broad s i n g l e t , 2.35, (4H); broad s i n g l e t , 1.88, (4H); s i n g l e t , 1.70, (4H) Chi6rinatiort of Protoadamantan-4-one To a solution of 2.0 g (13.3 mmole) of protoadamantan-4-one i n 10 ml of RCl^ i n a 25 ml 3-necked f l a s k equipped with condenser and drying tube at 0° was added 4.0 g (19.2 mmole) of PCl^ i n portions over a period of 1 hour. The solution was allowed to warm to room temperature and s t i r r e d overnight. The reaction mixture was poured into ice water, petroleum ether (30 - 60) added and the layers separated. The organic phase was washed with water and dried over MgSO^. Evaporation yielded a yellow o i l which consis ted of 3 components by glc (OV-17 100(2) ^ 200°, t - 7.4, 10.3, 11.8 min.) i n the r a t i o of 63:13:24. The compounds were isolat e d by preparative g l c . The f i r s t component was shown to be 4-chloroprotoadamantene (colourless o i l ) . MS - 170(16), 168(47), 133(81), 126(37), 113(32), 91(100) - 167 -IR - 1630(s), 1465(w), 1445(m), 1340(w), 1320(s), 1290(w), 1092(w), 1060(w) 1020(s), 950(w), 942(m), 905(m), 855(w) NMR (CC14) - m u l t i p l e t , 1.4 - 1.8, (8H); m u l t i p l e t , 2.2 - 2.6, (4H) ; mult i p l e t , J = 8 Hz, J = 2 Hz, 6.15, (1H) The minor component was assigned as 4,4-dichloroprotoadamantane, mp 98 - 99.5°. MS - 206(5), 204(9), 171(33), 169(100), 133(24), 113(13), 91(28) IR - 1455 (s) , 1340 (T?) , 1322 (w), 1308(m), 1180(m), 1162 (w), 1105 (w), 1062 (m) 1045(w), 1020(m), 980(sb), 955(s), 917(s), 892(s), 878(s), 840(m), 670(s) NMR (CC1A) - multiplets, 1.40 - 3.10, (14H) Analysis - C^H^C^ C H calculated 58.55 6.88 found 58.36 7.04 The t h i r d component was shown to be 1,2-dichloroadamantane, mp 179 -181° ( l i t 3 6 178 - 180°, 3 4183 - 185°) MS - 206(3), 204(6), 171(33), 169(100), 133(17), 113(8), 91(17), IR - I450(s), 1340(m), 1284(m), 1222(w), 1100(m), 1032(s), 972(mb), 955(w), 852(s), 700(mb) NMR (CCl^) - mu l t i p l e t s , 1.4 - 2.75, (13H); broad s i n g l e t , 4.25, (1H) The above reaction was repeated with 1.5 g (10.0 mmole) of proto-adamantan-4-one to y i e l d a l i g h t yellow o i l containing the same three products. This o i l was placed i n 50 ml of concentrated HCI and s t i r r e d under r e f l u x for 30 hours. The white s o l i d that was i n the condenser was cashed out with CHC1.J and added to the washing of the acid solution. The organic phase was washed with water and dried. Evaporation yielded a yellow s o l i d which was eluted with pentane down a short alumina column to y i e l d 1.08 g (53%) of 1,2-dichloroadamantane which was i d e n t i c a l i n a l l respects to the material collected by glc above. - 168 -1,2-Dibrbm6adamarttane The procedure of McKervey was followed"3**. To a solution of 710 mg (4.72 mmole) of protoadamantan-4-one i n TO ml of PBr^ at 0° was added portionwise over a period of 1 hour 2.50 g (5.22 mmole) of PBr,.. The yellow solution was warmed to room temperature and allowed to s t i r for 48 hours. The orange o i l was poured into ice water and worked up as above to y i e l d a yellow s o l i d . This was r e c r y s t a l l i z e d from 30-60 petroleum ether to y i e l d 0.64 g (51%) of colourless plates, mp 120 - 121° ( l i t 3 6 122 - 123°) MS - 294(2), 292(2), 215(100), 213(100), 133(26), 105(9), 91(29) IR - 1460(w), I443(s), 1356(w), 1340(m), 1308(w), 1283(m), 1260(w), 1208(w), 1190(m), 1100(m), 1024(s), 970(m), 960(m), 950(m), 932(w), 925(w),680(s) NMR (CC14) - mul t i p l e t s , 1.60 - 3.05, (13H); broad s i n g l e t , 4.46, (IH) Halogen Exchange on 1,2-Dlchlbrbadamantane The catalyst was prepared as before from 100 mg (3.7 mmole) of aluminum f o i l and 382 mg (1.50 mmole) of iodine i n 30 ml of C S 2 . After refluxing for 45 min. the solution was cooled to -50° i n a Dry I c e / i s o -propanol bath and 205 mg (1 mmole) of the 1,2-dichloride added. The reaction was worked up as before after 15 min. (glc indicated that s t a r t i n g material was a l l gone after 30 seconds) to y i e l d 405 mg of an orange s o l i d . Elution - 169 -with petroleum ether (30-60) down an alumina column yielded 320 mg (82%) of a white s o l i d which was r e c r y s t a l l i z e d from pentane, mp 107 -108.5° ( l i t 3 7 106 - 108°) MS - 388(6), 261(100), 216(3), 214(4), 134(20), 133(17), 105(6), 91(10) IR - 1460(w), 1440(s), 1350(w), 1338(m), 1302(w), 1280(m), 1257(m), 1200(w), 1172(m), 1145(m), 1100(m), 1020(s), 972(m), 955(m), 945(m) 922(m), 665(s) NMR (CC14) - mu l t i p l e t s , 1.64 - 3.16, (13H); s i n g l e t , 4.98, (1H) The same reaction was repeated using bromine to y i e l d a 78% y i e l d of 1,2-dibromoadamantane, i d e n t i c a l to that produced by the bromination of protoadamantan-4-one. Chlorine Exchange on 2,2-Dibf6m6adamaritane The catalyst was prepared as before from 300 mg (11.1 mmole) of aluminum f o i l i n 45 ml of CHCl^ at 0° with chlorine gas being passed through the solution. The mixture was warmed to room temperature a n d a small c r y s t a l of iodine added. After the exothermic reaction which consumed most of the aluminum f o i l had ceased the black solution was cooled to 0° a n d 300 mg (1.02 mmole) of the 2,2-dibromide added. The reaction was worked up as before after 1 minute to y i e l d an orange s o l i d . E lution down a short alumina column with petroleum ether (30-60) yielded 180 mg (87%) of a white s o l i d which was shown (by nmr) to consist of anti-1.4-dichloroadamantane (19%) and syn-1,4-dichloroadamantane (81%). - 170 -Iodine Exchange on 1,4-Dichlorbadamantane The catalyst was prepared as before from 200 mg (7.4 mmole) of aluminum f o i l and 380 mg (1.5 mmole) of iodine i n 40 ml of C S 2 . The active catalyst solution was cooled to 0° and 160 mg (0.78 mmole) of a 80:20 mixture of syn and anti-1 T3-dichloroadamantane was added. The reaction was worked up as before after 2 minutes to y i e l d a dark o i l which consisted of 1 peak by glc. E lution down a short alumina column with pentane yielded 220 mg (73%) of a l i g h t yellow s o l i d which was r e c r y s t a l l i z e d from pentane, mp 101 -102.5°. MS - 388(trace), 261(100), 216(6), 214(7), 134(19), 133(18), 105(6), 91(12) IR - 1470(w), 1442(s), 1340(m), 1322(w), 1298(w), 1282(s), 1242(m), 1154(s), 1100(m), 1018(s), 967(w), 834(m), 915(s) NMR (CC14) - mu l t i p l e t s , 2.02 - 2.64, (11H); doublet, J = 12 Hz, 3.20, (2H); si n g l e t , 4.84, (1H) Tef 1 4 3 There was no evidence by glc or nmr for any of the an£i-l,4-diiodide. Iodine Exchange on 2,2-Dichlbroadamaritane The catalyst was prepared as before using 200 mg (7.4 mmole) of aluminum f o i l and 720 mg (3.0 mmole) of iodine i n 30 ml of CS 2 < The active catalyst system was cooled to -50° i n an isopropahol/Dry Ice bath and 410 mg (2.0 mmole) - 171 -of the 2,2-dichloride added. The reaction was quenched after 1 minute to y i e l d a l i g h t pink solution which showed two peaks by glc . Evaporation yielded a dark orange o i l which was p u r i f i e d by t i c ( s i l i c a gel with 30-60 pet ether). Two major bands were separated and the components isolated by washing with chloroform. The f i r s t band yielded almost pure adamantanone (the CHCl^ solution was dark purple). The second f r a c t i o n consisted of mainly syn-1.4-diiodoadamantane with a small amount of 2-iodoadamantane. The above reaction was repeated but t h i s time the crude product was pu r i f i e d by column chromatography (alumina). Again, before chromatography only the two diiodide isomers were present but upon separation only the 1,4-diiodide was isolated along with 2-iodoadamantane and adamantanone. The supposed gem diiodide present i n the crude material could not be isol a t e d as i n the case of the bromine exchange reaction. l-ChlOro-3-ibdoadamar\tane H. To a solution of 1.0 g (2.53 mmole) of 1,3-diiodoadamantane i n 50 ml of spectrograde CCl^ i n a 3-necked f l a s k shielded from the l i g h t with o 47 aluminum f o i l at 0 was added 130/A<-£(2.58 mmole) of iodine monochloride The solution became dark purple and was followed by glc . An additional 45^ /u.-^ -of IC1 was added after 1 hour. The reaction mixture was poured into ice water after 2 hours and shaken with aqueous sodium b i s u l f i t e . The organic phase was washed with aqueous sodium carbonate, water and dried over MgSO^. Glc showed two peaks of equal in t e n s i t y (.OV-17 125(2) 1 6 > 250°, t = 5.2 and 7.8 min.). Evaporation yielded 0.92 g of a sti c k y yellow s o l i d - 172 -which was collected by glc to y i e l d 160 mg of the 1,3-dichloroadamantane and 190 mg of l-chloro-3-iodoadamantane. The dichloride was i d e n t i c a l i n a l l respects to an authentic sample. The chloroiodide had the following properties: mp 59.5 - 61° MS - 296(trace), 171(33), 169(100), 133(25), 113(10), 105(7), 93(10), 91(16) IR - 1452(s), 1338(s), 1318(s), 1285(s), 1262(w), 1246(w), 1145(w), 1103(m), 1022(s), 998(m), 958(s), 940(m), 840(s), 708(s) NMR - (CgHg) - unresolved t r i p l e t , 1.13, (2H), H 5; broad s i n g l e t , 1.42, (2H), H^; unresolved doublet, 1.80, (4H), H^; unresolved doublet, 2.08, (4H), H 2; s i n g l e t , 2.76, (2H), HI Analysis - C^H^CII C H calculated 40.50 4.76 found 40.71 4.74 1,4-Dichl6rbbicyclo£2.2.l}heptane9 To a solution of 11.27 g (48.5 mmole) of crude 1,2,3,4-tetrachloro-bicyclo/~2.2.i3hept-2-ene* i n 150 ml of absolute ethanol was added 200 mg of 10% Pd/C with 20.2 g (200 mmole) of triethylamine. This solution was shaken on a Parr Hydrogenator at 43 p s i for 1*2 hours. The s t a r t i n g material was t o t a l l y consumed as shown by glc. The catalyst was f i l t e r e d off and water added. The solution was washed well with chloroform and the organic phase was washed with d i l u t e HC1 and water. The dried solution was evaporated to y i e l d 8.5 g of a yellow s o l i d which was shown to consist of the * Prepared by Dr. J. McKinley i n 1971 - 173 -1,4-dichloride plus two impurities of longer rentention time i n the r e l a t i v e r a t i o of 8:1:1. Elution with petroleum ether (30-60) down an alumina column yielded 5.5 g (69%) of s t i c k y white cr y s t a l s which were r e c r y s t a l l i z e d from pentane to y i e l d white c r y s t a l s , mp 77 - 78° ( l i t 9 78 - 79°) IR (KBr) - 1450(m), 1312(a), 1264(a), 1240(m), 1210(a), 1010(a), 943(m), 857(a), 760(a) NMR (C 6H 6) - s i n g l e t , 1.90, (2H); AB quartet, J = 8 Hz, 1.50 and 1.83, (8H) 1,4-Dii6dbbicycl6/[2.2. l ] heptane The catalyst was prepared as before from 3.8 g (140 mmole) of aluminum f o i l and 15.4 g (60.6 mmole) of iodine i n 100 ml of carbon d i s u l f i d e . The solution was refluxed for 45 minutes then 1.0 g tffc.06 mmole) of 1,4-dichloro-bi c y c l o £2.2.l] heptane was added. The solution was s t i r r e d under r e f l u x f o r 94 hours and then worked up as before to y i e l d a d i r t y brown s o l i d . Elution with petroleum ether (30-60) down an alumina column yielded 960 mg (46%) of a l i g h t yellow s o l i d which was r e c r y s t a l l i z e d from pentane to y i e l d white c r y s t a l s , mp 100 - 101° ( l i t 5 2 101°) Further elution yielded 85 mg of a white s o l i d which was collected by preparative glc. mp 79 - 80°. MS - 234(9), 232(20), 230(16), 206(48), 204(100), 202(78), 197(43), 195(46), 170(16), 168(51), 166(54), 160(22), 158(35) IR (CS 2) - 1298(w), 1280(s), 1238(w), 1224(m), 1200(w), 1180(w), 1154(w), 1120(m), 1092(m), 1074(m), 1038(s), 1014(m), 968(m), 880(w), 862(m), 849(m), 800(w), 736(s) - 174 -NMR (C 6H 6) - mult i p l e t , 1.26-2.00 Analysis - C H I 36.22 3.07 0.00 The rest of the material was a dark, thick o i l of long retention time by glc (at least 3 peaks). The catalyst was prepared as before from 1.6 g (60 mmole) of aluminum f o i l and 10.02 g (40 mmole) of iodine i n 50 ml of reagent cyclohexane. After s t i r r i n g under re f l u x for 40 minutes, 4.5 g (27.2 mmole) of the 1,4-dichloride was' added. The reaction was worked up after r e f l u x i n g for 12 hours to y i e l d a yellow s o l i d . Elution with petroleum ether (30-60) down a s i l i c a gel column gave a small amount of side products; elution with di e t h y l ether yielded 6.5 g (73%) of a white s o l i d which was r e c r y s t a l l i z e d from pentane, mp 100 - 101°. IR (K3r) - 1440(w), 1308(m), 1267(m), 1230(w), 1202(m), 990(s), 825(s), 748(s) NMR <C6H6) - s i n g l e t , 2.00, (2H); AB quartet, J = 8 Hz, 1.78 and 1.40, (8H) The catalyst was prepared as before from 50 mg of aluminum f o i l and chlorine gas at 0° i n chloroform. A c r y s t a l of iodine was added and the solution refluxed i n an o i l bath. To this was added 50 mg of the 1,4-dichloride - 175 -and the solution s t i r r e d under re f l u x for 24 hours. Workup as before yielded a yellow s o l i d i d e n t i c a l i n a l l respects to the s t a r t i n g material. MR. The catalyst was prepared as before from 55 mg (2.0 mmole) of aluminum f o i l and 127 mg (0.5 mmole) of iodine i n 40 ml of carbon d i s u l f i d e . After s t i r r i n g for 40 minutes, 50 mg (.144 mole) of the 1,4-diiodide was added and the solution s t i r r e d under r e f l u x for 60 hours. Workup as before yielded a yellow s o l i d which was i d e n t i c a l to s t a r t i n g material i n a l l respects. Exo-2-bromobicyclo£"2.2. l ] heptane HBr / 7 \ B r 144 Procedure of Taylor was followed. To a solution of 3.2 g (32 mmole) of norbornene i n 40 ml of d i e t h y l ether i n a 100 ml 3-necked fla s k equipped with condenser and gas i n l e t tube at 0° was added dry HBr gas for a period of 1% hours. The solution was warmed to room temperature and allowed to s t i r overnight. The reaction mixture was poured into ice water and extracted with pentane. The organic layer was washed with aqueous sodium carbonate, water and dried over magnesium sulfate. Evaporation yielded a l i g h t yellow l i q u i d which was d i s t i l l e d to y i e l d 5.5 g (93%) of a colourless o i l , bp 45° (2.5 mm) ( l i t 1 4 5 96 - 97° (45 mm)) NMR (CDC13) - multiplets, 1.00 - 2.50, (10H); multiplet, 3.98, (IH) - 176 -Ex6-2-ibdobicycl oZ2.2.l7hept ane r Al J 2 >s C S 2 The catalyst was prepared as before from 675 mg (25 mmole) of aluminum f o i l and 2.05 g (8 mmole) of iodine i n 40 ml of carbon d i s u l f i d e . The catalyst was cooled to room temperature and 2.10 g (12 mmole) of 2-bromo-norbornane added. The reaction was stopped after 15 minutes and worked up as before to y i e l d an orange o i l . D i s t i l l a t i o n yielded 1.97 g (74%) of a l i g h t pink l i q u i d , bp 29° (1.8 mm) ( l i t 1 4 6 55 - 56° (3.0 mm)) NMR (CDC13) - mul t i p l e t s , 1.10 - 2.60, (10H); m u l t i p l e t , 4.00, (1H) 147 Separation bf c i s arid trans 4-fc-butylcyclbhexariol To an alumina column (1500 g) was placed 32.0 g of commercial cis/trans (30:70) 4-t-butylcyclohexanol and petroleum ether (30-60) was used as the elutant. After 14 l i t r e s of solvent (250 ml fractions) had been eluted 20% Et20/pet ether was used. After 19 l i t r e s pure d i e t h y l ether was used (fr a c t i o n #76). At f r a c t i o n #83 a white s o l i d began appearing (pure c i s alcohol). From here on 100 ml fractions were taken. Fractions #83 to #94 contained 19.8 g of pure trans alcohol while fractions #95 - #100 contained 1.8 g o f a mixture of the two alcohols. O H H C T - 177 -Cis IR (CC1 4) - 3650(w), 3450(w), 1475(m), 1455(m), 1385(w), 1360(m), 1170(w), 1055(s), 1035(w), 980(w), 900(w) NMR (CDC13) - s i n g l e t , 0.87, (9H); m u l t i p l e t s , 1.2 - 2.0, (9H); m u l t i p l e t , 4.04, (IH) Trans IR (CC14) - 3650(w), 3450(w), 1475(m), 1455(m), 1385(w), 1360(m), 1220(m), 1175(w), 1025(m), 1005(m), 955(s), 905(w) NMR (CDC13) - s i n g l e t , 0.87, (9H) ; m u l t i p l e t s , 1.0 - 2.0, (9H); broad s i n g l e t , 3.48, (IH) Brominatiort of trans 4-t-butvlcyclohexanol To a 3-necked f l a s k equipped with condenser and dropping funnel was placed 1.56 g (10.0 mmole) of trans 4-t-butylcyclohexanol. The f l a s k was cooled to 0° and the dropping funnel charged with 2.98 g (11.0 mmole) of PBr 3 which was added dropwise over a period of lh hours. The solution was allowed to warm to room temperature and s t i r r e d overnight. The reaction was quenched by the cautious addition of water. Addition of petroleum ether (30-60) and washing with aqueous sodium carbonate yielded a colourless solution which was shown by nmr to consist of the 3 and 4-bromo-t-butyl-cyclohexane isomers plus 4-£-butylcyclohexene. The r e l a t i v e r a t i o s were 148 149 1:4:1 for the o l e f i n ; a x i a l bromides; e q u i t o r i a l bromides ' NMR (CDC1 3) - s i n g l e t , 5.75, o l e f i n ; m u l t i p l e t , 4.65 - 4.85, a x i a l bromides; mult i p l e t , 3.75 - 4.20, e q u i t o r i a l bromides - 178 -Chloririatibrt of cis/tfarts 4-t-butylcvclohexariol To a 3-necked round bottomed f l a s k equipped with condenser and dropping funnel was added 3.12 g (20.0 mmole) of cis/trans (30:70) 4-£-butylcyclohexanol. The flas k was placed i n an o i l bath at 80° and the funnel was chargedwith 2.0 ml (31.0 mmole) of SOC^. The dropwise addition took 20 minutes and the solution was s t i r r e d at 80° for 2 hours. The solution was cooled to room temperature and cautiously added to ice water. To th i s was added petroleum ether (30-60), the layers separated, and the organic phase washed with aqueous sodium carbonate and ^ater. Evaporation of the dried solution yielded a yellow o i l which was shown by nmr to consist of ^ 90% 4-£-butylcyclohexene. An a n a l y t i c a l sample was obtained by preparative g l c . IR - 1660(m), 1475(s), 1385(m), 1360(s), 1300(w), 1222(m), 1175(w), 1145(m), 1045(w), 942(w), 913(m), 876(m), 703(s) NMR. (CDC13) - s i n g l e t , 0.87, (9H); m u l t i p l e t s , 1.2 - 2.2, (6H); s i n g l e t , 5.25, (2H) Chlbrination of cis-4-t-butylcyclohexanol O H In a 2-necked f l a s k equipped with condenser and dropping funnel •containing 2.0 ml (31.0 mmole) of SOCl^ was placed 2 ml of pyridine and - 179 -3.12 g (20.0 mmole) of cis-4-t-butylcyclohexanol"'" 5^. The solution was heated to 80° and the SOC^ added dropwise over a period of 30 minutes. The solution was then s t i r r e d for lh hours. The cooled solution was cautiously added to water and worked up as before. Analysis by nmr showed the product to consist of the o l e f i n (61%), c i s chloride (14%) and the trans chloride (25%). This mixture was placed with 1.0 g of KOH i n 30 ml of 95% ethanol and s t i r r e d under re f l u x for 16 hours"'"51. The cooled mixture was poured Into water and extracted with pentane. Evaporation yielded a dark brown o i l which was collected by glc to y i e l d 650 mg of the o l e f i n plus 510 mg of the trans-4-t-butylcyclohexylchloride. Further analysis showed that the chloride contained 7% of the c i s isomer as w e l l . IR - 1472(m), 1442(m), 1384(m), 1360(s), 1340(w), 1264(m), 1212(m), 1178(m), 1035(w), 998(s), 930(w), 900(m), 880(m) NMR (CC14) - s i n g l e t , 0.93, (9H); mu l t i p l e t s , 1.0 - 2.25, (9H); multiplet 3.69, (IH) Chlorination of trans-4-t-butylcyclohexartol H H -SQQ CI H The above reaction was repeated with the trans alcohol to y i e l d a yellow o i l which contained the o l e f i n (65%) and chloride (35%). Collection - 180 -by glc yielded the c i s chloride which was contaminated with 6% of the trans isomer. IR - 1475(m), 1440(m), 1385(m), 1360(s), 1310(m), 1260(m), 1210(w), 1175(w) 1024(m), 1000(m), 927(w), 910Cm), 862(s), 693(s) NMR (CC14) - s i n g l e t , 0.84, (9H); mu l t i p l e t s , 1.4 - 2.2, (9H); multiplet 4.37, (IH) Chlorination of cis/trans 4-t-butylcycldhexanol The above reaction was repeated with the commercial alcohol (30% c i s , 70% trans) to give a l i g h t yellow o i l which consisted of the o l e f i n (58%) and the chlorides (42%). C o l l e c t i o n by glc yielded the t-b u t y l chlorides which consisted of 70% c i s and 30% trans by nmr integration. Iodine exchange of cis/trarts-4-t-bUtylcyclOhexylchlorlde The catalyst was prepared as before from 80 mg (3 mmole) of aluminum f o i l and 190 mg (0.75 mmole) of iodine i n 30 ml of carbon d i s u l f i d e . After r e f l u x i n g for 40 minutes the solution was cooled to room temperature and 156 mg (0.84 mmole) of the 4-t-butylcyclohexyl chlorides added (70% c i s , 30% trans). The reaction was worked up after 2 minutes to y i e l d 220 mg (94%) of a l i g h t yellow o i l which darkened (purple) rapidly on exposure to l i g h t . Glc showed one peak (no st a r t i n g material) and nmr showed i t to - 181 -consist of the two isomeric iodides i"" m by vir t u e of the two OC hydrogens. (CCl^ solution) c i s iodide 4.94 (32%) trans iodide 4.04 (68%) The same reaction was repeated on the pure c i s and trans 4-t-butyl-cyclohexyl chlorides at room temperature and further studies were done at lower temperatures i n Dry Ice solvent baths. . In each case the catalyst was prepared as before and cooled to the appropriate temperature. The cyclohexyl chloride was dissolved i n carbon d i s u l f i d e and cooled to the temperature of the ice bath before addition. Analysis was again made by nmr. - 182 -2-Bfomobctane To a 200 ml 3-necked round bottomed f l a s k equipped with s t i r r i n g bar and dropping funnel containing 4.5 ml (13g, 48.0 mmole) of PBr^ was placed 6.0 g (46.0 mmole) of 2-octanol. The fl a s k was immersed i n an ice bath at 0° and the PBr^ added dropwise over a period of lh hours. The solution was warmed to room temperature and allowed to s t i r overnight. The mixture was then heated at 80° for 1 hour and poured into i c e water and extracted with petroleum ether (30-60). The organic phase was v:ashed with aqueous sodium carbonate, water then dried over M g S 0 4 . D i s t i l l a t i o n yielded 5.0 g (75%) of a colourless l i q u i d , bp 90° (30 mm), ( l i t 1 5 3 76° (18 mm)) The exchange on 2-bromooctane at 25° gave a 85% y i e l d of the corresponding iodide. IR (neat) - 1460(s), 1376(m), 1280(w), 1250(w), 1202(m), 1165(s), 1135(s), 1078(wb), 790(m), 728(m) NMR (CS2) - m u l t i p l e t s , 0.9 - 2.0, (16H); m u l t i p l e t , 4.06, (1H) Iodine Exchange on (+)-2-Brdm66ctarie Br C S 2 2 - } I 99.78 mg i n 5.0 ml of CS c<= +0.079 c e l l constant = 0.744 = (+) 100 x 0.079 x .05 x 0.744 0.1 x .09978 - 183 -£ c J D = +29.4° 100% pure- 44.2° purity =66.5% The catalyst was prepared as before and the reaction was done at four di f f e r e n t temperatures with approximately 65 mg of the o p t i c a l l y active bromide each time. The product was i d e n t i c a l by IR, glc and nmr to that of the reaction using racemic material. The reaction i n a l l cases was quenched after 2 minutes to give an 82% y i e l d of the corresponding iodide. Temperature • Rotation of Iodide +00% pure obs corr 25° 0.0° 0.0° 0° -2.2° -3.3° -53° -8.7° -13.1° -65° -9.8° -14.7° 6 4 . 2 ° Hexabromocyclopentadiene CIg C S 2 Br 6 The catalyst was prepared from 2.16 g (80 mmole) of aluminum f o i l and 2.75 ml (8.0 g, 50 mmole) of l i q u i d bromine i n 40 ml of carbon d i s u l f i d e . After r e f l u x i n g for 40 minutes the aluminum f o i l had been torn up to small pieces and the solution was a l i g h t orange. The mixture was cooled to room temperature and 2.54 g (10.0 mmole) of hexachlorocyclopentadiene was added with s t i r r i n g . The reaction was quenched and worked up as before a f t e r 20 minutes to y i e l d 4.7 g (93%) of a dark o i l which s o l i d i f i e d on standing. Tic showed one spot (R f = 0.91, SM = 0.73) on s i l i c a gel plates with petroleum ether (30-60) as the developing solvent. R e c r y s t a l l i z a t i o n from pentane yielded pale yellow c r y s t a l s , mp 83 ~ 84° ( l i t 1 5 ' * 82 ~ 83°) |R ( C S 2 ) - 1192(s), 1155(w), 1138(w), 1095(m), 910(m), 810(w), 745(s), 715(m) 07 Br, 5 6 - 184 -IR (CS 2) of C 5C1 6 - 1225(s), 1185(m), 1140(a), 1024(w), 978(w), 968(w), 862 (w), 807 ( s ) , 7.10 (s) , 680 (s) The catalyst was prepared as before from 640 mg (24 mmole) of aluminum f o i l and 2.0 g (8 mmole) of iodine i n 30 ml of carbon d i s u l f i d e . After 40 minutes the solution was cooled to 0° and 930 mg (10 mmole) of 1-chlorobutane was added. Workup as before after 2 minutes yielded 1.23 g (68%) of a l i g h t pink l i q u i d i d e n t i c a l i n a l l respects to authentic 1-iodobutane. Analysis by nmr showed no trace of the secondary or t e r t i a r y isomers. Iodocyclohexane The catalyst was prepared as above from 500 mg (18.5 mmole) of aluminum f o i l and 2.45 g (9.2 mmole) of iodine i n 40 ml of carbon d i s u l f i d e . A f t e r s t i r r i n g under r e f l u x for 40 minutes the solu t i o n was cooled to room temperature and 2.0 g (12.3 mmole) of cyclohexyl bromide was added. Workup as before a f t e r 2 minutes yielded 2.04 g (78%) of a colourless l i q u i d , bp 38° (2.7 mm) ( l i t 1 5 3 68° (10 mm)) IR (CS 2) - 1340(m), 1330(m), 1240 ( 3 ) , 1170(s), 1095(s), 1080Cw), 1035(w), 1020(m), 992(s), 920Cm), 885(s), 870(m), 855(m), 814(s) NMR (CS 2) - m u l t i p l e t s , 1.20 - 2.30, (1111) ; mu l t i p l e t , 4.27, (IH) 1-Iodohutane - 185 -Iodine Exchange on Bromobenzene >' N R The catalyst was prepared as before from 500 mg (18.5 mmole) of aluminum f o i l and 2.54 g (10.0 mmole) of iodine in 40 ml of carbon disulfide. After refluxing for 40 minutes, 500 mg (3.19 mmole) of bromobenzene was added. No reaction was observed after 24 hours, so a portion of the solution was added to a carbon disulfide solution of 1-chloroadamantane. Complete conversion to iodoadamantane was observed. The solution was worked up after refluxing for 6 days to yield only starting material. The same was found for the reaction of 1,2-dichlorobenzene and 1-bromonaphthalene -no iodide formation occurred. Exchange on 1,2,3,4-tetrachlorbbicycloJ2.2.Jhept-2-ene It — ) NR The catalyst was prepared as before from 90 mg (3.9 mmole) of aluminum f o i l and 246 mg (0.97 mmole) of iodine in 20 ml of carbon disulfide. After refluxing for 40 min., 100 mg (0.43 mmole) of the tetrachloride was added. No reaction had occurred after 2 hours so a portion of the mixture was added to a carbon disulfide solution of 1-chloroadamantane. An immediate 100% conversion to 1-iodoadamantane occurred. The reaction was worked up after 24 hours to yield only residual starting material. - 186 -Photochemical Reactions of Bridgehead Halides A) Using Alcohols as Solvent To a quartz tube was added 215 mg (1 mmole) of 1-bromoadamantane with 70 ml of the alcohol being used. The solution was degassed for 10 minutes with L grade nitrogen, a condenser added, and i r r a d i a t e d for approximately eight to twenty hours. Analysis by glc showed no trace of s t a r t i n g material with two products, adamantane and the alkoxyadamantane. With R = CH3- and CH3CH2~ the y i e l d s of adamantane were 21 and 19% respectively. The solution was washed with aqueous sodium b i s u l f i t e , then petroleum ether was added and the layers separated. The organic phase was washed with aqueous sodium carbonate, water, and then dried over anhydrous magnesium sulfate. Preparative glc yielded the pure adamantyl ether. The same procedure was used i n the photolysis of 262 mg (1 mmole) of adamantyl iodide. Here the reaction was much faster and the y i e l d of adamantane i n a l l cases was less than 5%. a) R = CH3-MS - 166(25), 135(8), 124(5), 109(100), IR - 1442(m), 1340(m), 1300(m), 1200Cw), 1165(m), 1105(s), 1085(s), 1040(m) 890(m) NMR (C^ H^ .) - unresolved t r i p l e t , 1.51, (6H) , £ • unresolved doublet, 1.73, (6H),p ; broad s i n g l e t , 2.00, (3H), tf* ; s i n g l e t , 3.13, (3H), -0CH3 - 187 -b) R = CH3CH2- mp 16 - 17° ( l i t 1 0 2 15 - 15.5°) MS - 180(41), 152(9), 135(22), 134(11), 123(100), 95(53), 79(20) IR - 1450(m), 1385(w), 1350(m), 1300(m), 1180(w), 1108(s), 1080(s), 1050(m), 975(m), 950(m), 865(m) NMR (C &H 6) - t r i p l e t , J = 7 Hz, 1.15, (3H), -CH3; unresolved t r i p l e t , 1.47, (6H), S ; unresolved doublet, 1.72, (6H) ft ; broad s i n g l e t , 1.97, (3H), ; quartet, J = 7 Hz, 3.33, (2H), -OCH2 c) R = -CH(CH 3) 2 mp 18 - 19° ( l i t 1 0 2 18.5 - 19.5°) MS - 194(51), 179(11), 151(28), 137(100), 135(41) IR - 1465 (m), 1375 (ro) , 1360 (m), 1350 (m), 1300 (m), 1170 (m), 1120 (in), 1105 ( s ) , 1075(s), 995(s), 965(w), 935(w), 900(m) NMR (C 6H 6) - doublet, J = 6 Hz, 1.10, (6H), -CH3; unresolved t r i p l e t , 1.50, (6H), £ ; unresolved doublet, 1.70, (6H),^ ; broad s i n g l e t , 1.97, (3H), K ; mult i p l e t , J = 6 Hz, 3.72, (IH), -OCH d) R = -CH2CH2CH3 MS - 194(70), 137(100), 135(92), 95(70) IR - 1450(m), 1350(m),1300(m), 1185(w), 1110(s), 1085(s), 1058(w), 1000(m), 935(w), 905(w) NMR (C 6H 6) - t r i p l e t , J = 7 Hz, 0.95, (3H), -CH3; unresolved t r i p l e t , 1.50, (6H), & ; unresolved doublet, 1.76, (6H), JB ; broad s i n g l e t , 2.00, (3K),X ; mu l t i p l e t , 1.40 - 1.60, (2H), CH2; t r i p l e t , J = 7 Hz, 3.30, (2H), -0CH2 e) R = -CH2CH2OH mp 34 - 35° ( l i t 1 5 5 35 - 36°) MS - 196(16), 166(3), 165(5), 139(7), 135(100) IR-3450(w), 1453(m), 1395(w), 1360(w), 1348(m), 1300(m), 1200(w), 1178(w), 1115(sb), 1100(w), 1090(s), 1070(s), 1050(s), 975(m), 945(m), 890(m), 850(wb) - 188 -NMR ( C ^ ) - s i n g l e t , 0.93, (IH), -OH; unresolved t r i p l e t , 1.50, (6H), £ ; unresolved t r i p l e t , 1.65, (6H), ft ; broad s i n g l e t , 1.97, (3H), Q* ; multiplet, 3.45, (4H) , -OCH2CH20-f) R = CH2CH2OCH3 - 210(100), 153(4), 135(100), 93(20), 80(26) IR - 1445(m), 1360(w), 1350(m), 1300(m), 1240(w), 1200(m), 1120(sb), 1090(s), 1038(w), 983(m), 960(w), 924(m), 880(w) NMR (C 6H &) - unresolved t r i p l e t , 1.47, (6H), £ ; unresolved doublet, 1.69, (6H),£ ;broad s i n g l e t , 1.96, (3H) o"; s i n g l e t , 3.14, (3H), -0CH3; mul t i p l e t , 3.42, (4H), -OCH2CH20-Analysis - C 13 H 22°2 C H calculated 74.24 10.54 found 74.16 10.60 XCH g) R = -C-CinCH N.H m - 208(3), 179(17), 152(4), 135(100) IR - 1448(m), 1362(m), 1350(m), 1300(w), 1165(w), 1105(sb), 1080(s), 1030(m), 1000(m), 945(w), 880(w) NMR (C 6H 6) - t r i p l e t , J = 7 Hz, 0.93, (3H), -CH3; doublet, J = 7 Hz, 1.12, (3H), -CH3; mu l t i p l e t , 1.40 - 1.60, (2H), -CH2; unresolved t r i p l e t , 1.54, (6H), £ ; unresolved doublet, 1.75, (6H), p> ; broad s i n g l e t , 2.01, (3H), ft* ; mult i p l e t , J = 7 Hz, 3.55, (IH), -OCH High Resolution MS - C^H^O calculated 208.3468 found 208.3470 h) R = CH2CH2CH2CH3 MS - 208(50), 151(71), 135(100), 95(43) IR - 1450(m), 1350(m), 1300(m), 1185(w), 1115(s), 1085(s), 1025(w), 975(wb), 935(w), 915(w) - 189 -NMR (C 6H 6) - t r i p l e t , J = 7 Hz, 0.91, (3H), -CH3; unresolved t r i p l e t , 1.51, (6H), $ 5 mu l t i p l e t , 1.35 - 1.60, (4H) , -CH2CH2~; unresolved doublet, 1.74, (6H),j5 ; broad s i n g l e t , 1.99, (3H), X 5 t r i p l e t , J = 7 Hz, 3.34, (2H), -0CH2 High Resolution MS - C^H^O calculated 208.3468 found 208.3465 i ) R = -CH2CH2CH2CH2CH3 MS - 222(16), 165(32), 135(100), 95(32) IR - 1450(m), 1350(m), 1300(m), 1285(w), 1185(w), 1115(s), 1090(s), 1055(w), 940(wb), 915(w) NMR (C gH 6) - t r i p l e t , J = 7 Hz, 0.89, (3H), -CH3; m u l t i p l e t , 1.35 -1.60, (6H), -(CH 2) 3~; unresolved t r i p l e t , 1.51, (6H), £ ; unresolved doublet, 1.75, (6H), f> ; broad s i n g l e t , 1.99, (3H), fc* ; t r i p l e t , J = 7 Hz, 3.34, (2H), -0CH2  Analysis - C 1 5 H 2 6 ° C H calculated 81.02 11.78 found 80.98 11.90 SolVolysis of Monohalides iri Methanol A solution of 100 mg (.46 mmole) of 1-bromoadamantane i n 25 ml of methanol was s t i r r e d under refluxing conditions. After 6 hours 10% reaction had occurred with 60% after 24 hours. S i m i l a r l y , a solution of 100 mg (.38 mmole) of 1-iodoadamantane i n 25 ml of ref l u x i n g methanol showed 35% reaction after 6 hours and 90% after 24 hours. The photochemical reactions were completely finished i n 8 hours and 2% hours respectively. - 190 -I CH3OH A solution of 262 mg (1 mmole) of 2-ioddadamantane i n 70 ml of methanol was ir r a d i a t e d through quartz i n the same manner as the bridgehead isomer. Workup as before after 4 hours yielded the secondary ether (96%) plus adamantane (4%). IR - 1462(w), 1455(m), 1380(m), 1365(w), 1223(w), 1200(m), 1182(m), 1105(sb), 985(m), 975(m), 940(m), 910(w) At NMR (C 6H &) - s i n g l e t , 3.18, (4H); doublet, J = 11 Hz, 2.21, (2H); doublet, J =11 Hz, 1.31, (2H); mul t i p l e t s , 1.58 - 1.98, (10H) 1,3-Dimethoxyadanantane A w e l l degassed solution of 388 mg (1 mmole) of 1,3-diiodoadamantane i n 70 ml of methanol was i r r a d i a t e d for 4 hours through quartz. The diether MS - 196(26), 165(19), 139(100), 109(28), IR - 1455(m), 1365(m), 1325(w), 1300(m), 1280(w), 1190(ra), 1150(m), 1115(s), 1072(s), 1050(m), 980(m), 915(s), 875(w) s was the major product (OV-17 125(4) — — > 200 , t = 8.4 min.) with a 4% y i e l d of adamantane. Workup as before yielded the crude ether which was p u r i f i e d by g l c . - 191 -NMR (C,H.) - unresolved doublet, 1.28, (2H), £ 5 broad doublet, 1.58, (8H), ; s i n g l e t , 1.81, (2H), p ; broad s i n g l e t , 2.02, (2H), ; s i n g l e t , 3.10, (6H), -0CH3 A n a l y s i s " C12H20°2 _C_ _H_ calculated 73.43 10.27 found 73.13 10.41 An authentic sample of the dimethoxyl compound was prepared by the 63 method of Owen . Into a 3-necked f l a s k equipped with condenser, s t i r r i n g bar and drying tube was placed 3.0 g (10.2 mmole) of freshly prepared Ag0^5° and 100 ml of freshly d i s t i l l e d methanol. The mixture was s t i r r e d under reflux and followed by glc. Additional AgO was added (1.5 g every 24 hours) and the reaction cooled and f i l t e r e d a f ter 92 hours. Evaporation yielded a thick yellow o i l which was eluted with petroleum ether (30-60) down an alumina column. The f i r s t fractions yielded 50 mg of a white s o l i d while further elution gave the diether which was d i s t i l l e d , bp 63 - 65° (0.17 mm) to give a colourless o i l i d e n t i c a l i n a l l respects to the photolytic product. The minor component was found to be 7-methylenebicyclo^3.3.l]-nonan-3-one, mp 160 - 161° ( l i t 1 5 7 161 - 162°) IR - 1720(s), 1460(m), 1400(m), 1360(w), 1335(m), 1220(m), 1155(w), 1100(w), 1090(m), 1060(m), 905(s), 880(m) NMR (CS 2) - s i n g l e t , 1.88, (2H); broad m u l t i p l e t , 2.28, (10H); s i n g l e t , 4.65, (2H) - 192 -Attempted Synthesis of 1-t-butoxyadamaritane A solution of 262 mg (1 mmole) of l-iodbadamantane i n 70 ml of spectrograde _t-butanol was ir r a d i a t e d through quartz for 4 hours. Workup as before yielded a white s o l i d which was i d e n t i c a l i n a l l respects to 1-adamantanol. Careful drying and d i s t i l l a t i o n of the .t-butanol produced the same result with no trace of the t-butoxyadamantane. Ir r a d i a t i o n i i i the presence of cyanide ion A solution of 140 mg (0.65 mmole) of 1-bromoadamantane with 200 mg (4.08 mmole) of NaCN i n 75 ml of freshly d i s t i l l e d CH^ OH was ir r a d i a t e d through quartz for 24 hours. Workup as before yielded a yellow s o l i d which consisted of adamantane (41%) and 1-methoxyadamantane (59%). The same reaction was repeated with 170 mg (0.65 mmole) of 1-iodo-adamantane and 150 mg (3.06 mmole) of NaCN i n 75 ml of CII^OH. The reaction was worked up after 2 hours to y i e l d adamantane (15%) and 1-methoxyadamantane (85%). There was no evidence for any 1-cyanoadamantane i n either reaction. - 193 -Ir r a d i a t i o n i n DMSO with added NaCN DM SO CN" N A solution of 270 mg (1.03 mmole) of 1-i'odoadamantane with 300 mg (6.13 mmole) of NaCN i n 75 ml of freshly d i s t i l l e d dimethyl' sulfoxide was irr a d i a t e d through quartz for 5 hours. The solution was worked up as before to y i e l d a yellow o i l shown to contain residual solvent. The o i l was dissolved i n petroleum ether (30-60) and washed f i v e times with water and redried to y i e l d a white s o l i d . Glc showed i t to consist of adamantane (4%), 1-adamantanol (88%), and 1-cyanoadamantane (8%). The three products were collected by glc and were i d e n t i c a l i n a l l respects to authentic samples. The same reaction was repeated i n the absence of NaCN re s u l t i n g i n a quantitative y i e l d of 1-adamantanol. I r r a d i a t i o n of 1,3-Dichlbrbadamaritane A degassed solution of 150 mg (0.73 mmole) of 1,3-dichloroadmaf-tane i n 70 ml of absolute ethanol was ir r a d i a t e d through quartz as before for 45 hours. Workup as before yielded a white s o l i d which was shown to consist of a 1:1 mixture of s t a r t i n g material and 1-chloroadamantane. There was no trace of any ethoxy adamantanes. - 194 -ft h (3 EtOH rOEt s A wel l degassed solution of 400 mg (1.03 mmole) of 1,3-diiodoadamantane i n 70 ml of absolute ethanol was ir r a d i a t e d through quartz for 10 hours. Workup as before yielded a yellow o i l which was collected by g l c . MS - 224(39), 179(28), 167(100), 131(10), 123(16), 111(9), 95(11), 93(11) IR - 1448(m), 1382(m), 1360(w), 1344(m), 1322(w), 1300(m), 1280(w), 1122(s), HOO(msh), 1076(s), 1002(m), 880(w) NMR (CgHg) - t r i p l e t , J = 7 Hz, 1.15, (6H), -CH3; unresolved t r i p l e t , 1.29, (2H), £ ; doublet, J = 3 Hz, 1,62, (8H), p& ; s i n g l e t , 1.86, (2H), P ; broad s i n g l e t , 2.06, (2H),o"; quartet, J = 7 Hz, 3.33, (4H), -0CH2 Hjgh Resolution MS - C w H 9 A 0 9 calculated 224.1775 A solution of 400 mg (1.13 mmole) of 1,3-diiodoadamantane i n 70 ml of 1-propanol (degassed w e l l with nitrogen) was i r r a d i a t e d through pyrex for 11 hours. Workup as-before yielded a yellow o i l which was collected by glc. MS - 252(45), 195(100), 193(74), 153(16), 151(32), 111(18), 95(24), 93(26) IR - 1455(m), 1345(m), 1320(w), 1300(m), 1120(s), 1078(s), 1030(m), 932(w), found 224.1758 908 (m) - 195 -NMR (C 6H 6) - t r i p l e t , J = 7 Hz, 0.93, (6H), -CH3; unresolved t r i p l e t , 1.31, (2H), £ ; mu l t i p l e t , 1.42 - 1.70, (4H), -CH2-; broad doublet, 1.62, (8H),£& ; s i n g l e t , 1.85, (2H) , p ; broad s i n g l e t , 2.08, (2H), ; quartet, J = 7 Hz, 3.27, (4H), -0CH-High Resolution MS - C 1 6H 2 g0 2 calculated 252.2088 found 252.2100 1,3-Diis6prop6xyadamaritane iPrOH hJ2_ A well degassed solution of 400 mg (1.03 mmole) of 1,3-diiodoadamantane i n 70 ml of reagent 2-propanol was ir r a d i a t e d through quartz for 17 hours. Workup as before yielded a thick yellow o i l which was collected by glc. MS - 252(40), 195(82), 193(66), 167(13), 153(32), 152(17), 151(100), 150(15), 111(63), 109(19), 107(16), 95(34), 93(33) IR - 1450(m), 1376(w), 1360(m), 1342(w), 1320(w), 1300(w), 1175(w), 1130(m), 1108(s), 1048(s), 980(mb), 912(w) NMR (CgHg) - doublet, J = 6 Hz, 1.09, (12H), -CUjj unresolved t r i p l e t , 1.30, (2H),£ ; doublet, J = 3 Hz, 1.58, (8H),£& ; s i n g l e t , 1.80, (2H), p ; broad s i n g l e t , 2.05, (2H), o" ; mul t i p l e t , J = 6 Hz, 3.72, (2H), -CH High Resolution MS - C 1 6H 2 80 2 calculated 252.2088 found 252.2111 - 1 9 6 -1,3,5-Trimethbxyadamarttane A solution of 100 mg (.19 mmole) of 1,3,-5-triiodoadamantane i n 70 ml of methanol was degassed with nitrogen and ir r a d i a t e d through quartz for 6 hours. The t r i e t h e r was the major product with a 6% y i e l d of adamantane. The ether was p u r i f i e d by glc. MS - 226(45), 195(100), 169(90), 139(58), 123(89) IR - I445(m), 1350(w), 1315(m), 1290(m), 1220(w), 1185(m), 1230(m), 1180(sb), 1050(w), 1010(w), 970(m), 920(ra) NMR (C &H 6) - doublet, 1.44, (6H ) , p S £ ; unresolved doublet, 1.73, (6H),^p£; mul t i p l e t , 2.03, (IH), £ ; s i n g l e t , 3.06, (9H), -0CR\ Analysis - C 1 3 H 2 2 0 3 H calculated 6 8 . 9 9 9 . 7 9 found 6 9 . 0 6 9 . 7 4 A degassed solution of 300 mg (1.04 mmole) of 1,3-dimethyl-5-iodo-adamantane i n 70 ml of methanol was ir r a d i a t e d through quartz for 3 hours. Workup as before yielded the crude ether containing 5% of 1,3-dimethyl-adamantane. P u r i f i c a t i o n was by preparative glc. MS - 194(47), 163(39), 137(100), 123(86), 107(39), 91(14) - 197 -IR - I450(s), 1360(w), 1340(m), 1330(w), 1315(m), 1290(s), 1145(m), 1090(sb), 990(m), 960(m), 930(m), 860(m) — ( C 6 H 6 ) " s i n S l e t > "0.85, (6H), -CH3; s i n g l e t , 1.01, (2H), U ; unresolved doublet, 1.20, (4H), H 3; s i n g l e t , 1.41, (4H), H 2; unresolved doublet, 1.60, (2H), H 5; mult i p l e t , 2.08, (1H), H^; s i n g l e t , 3.16, (3H), -0CH3 Analysis - C^H 20 C H calculated 80.35 11.41 found 80.22 1,3-Dimethbxy-5,7-dimethyladamantane 11.44 " ^  A degassed solution of 300 mg (0.72 mmole) of l,3-diiodo-5,7-dimethyl-adamantane i n 70 ml of methanol was ir r a d i a t e d through quartz for 4 hours. Workup as before gave the crude ether containing 4% of 1,3-dimethyladamantane. P u r i f i c a t i o n was made by preparative g l c . MS - 224(39), 193(89), 153(100), 137(70), 121(55), IR - 1460(m), 1380(w), 1345(m), 1300(w), 1250(wb), 1220(m), 1210(m), 1195(w), 1095(sb), 1020(w), 970(m), 915(m), 855(m) NMR (CS 2) - s i n g l e t , 0.89, (6H), -CH3; s i n g l e t , 1.01, (2H), H ; s i n g l e t , 1.22, (8H), H 2; s i n g l e t , 1.45, (2H), H 3; s i n g l e t , 3.04, (6H), -0CH3 Analysis - C 1^ H24°2 C H calculated 74.95 10.78 found 74.76 10.70 - 198 -Ir r a d i a t i o n of 1,3-Dibforrtoadamantane JUL C H 3 O H A degassed solution of 300 mg (1.02 mmole) of 1,3-dibromoadamantane i n 70 ml of methanol was irra d i a t e d through quartz for 16 hours (no sta r t i n g material by g l c ) . Analysis showed the products to consist of adamantane (5%), 1-methoxyadamantane (31%), and 1,3-dimethoxyadamantane (64%) by c o l l e c t i o n and comparison to authentic samples. Repetition of the experiment showed two intermediate products which disappeared during the course of the reaction. When stopped after 6 hours the products consisted of adamantane (2%), 1-methoxyadamantane (27%), 1-bromoadamantane (17%), 1,3-dimethoxyadamantane (33%), l-bromo-3-methoxy-adamantane (18%), and residual 1,3-dibromoadamantane (3%). (OV-17 125(4) ^ 200 , t = 2.0, 5.4, 6.7, 7.4, 8.4, 9.8 minutes). Again a l l the products were collected by glc and were i d e n t i c a l to authentic samples except for the bromo-ether. mp 14.5 - 16.0° H> >CH3 "3 MS - 244(trace), 165(100), 133(4), 123(4), 109(35) IR - 1458(m), 1360(w), 1340(m), 1320(m), 1290(m), 1270(w), 1190(m), 1150(w), 1110(s), 1090(s), 1040(s), 960(s), 895(s), 675(s) NMR (C 6H 6) - unresolved t r i p l e t , 1.21, (2H), Ry broad s i n g l e t , 1.49, (4H) - I I 3 ; broad s i n g l e t , 1.83, (2H), H^; unresolved doublet, 2.06, (4H), H 2; si n g l e t , 2.31, (2H), s i n g l e t , 2.98, (3H), -0CH3 - 199 -Analysis - C..H BrO C H calculated 53.89 6.99 found 54.11 7.12 Ir r a d i a t i o n of 1,3-Dibfbmb-5,7-dimethyladamantane B r r A degassed solution of 300 mg CO.93 mmole) of l,3-dibromo-5,7-dimethyladamantane i n 70 ml of methanol was i r r a d i a t e d through quartz for 12 hours (s t a r t i n g material a l l gone). Workup as before and c o l l e c t i o n by glc showed the products to consist of 5% 1,3-dimethyladamantane, 34% 3 -dimethyl-5-methoxyadamantane and 61% of l,3-dimethoxy-5,7-dimethyladamantane. The reaction was repeated and stopped a f t e r 6 hours to y i e l d s i x products, i n the following r a t i o s : 1,3-dimethyladamantane (4%), 1,3-dimethyl-5-methoxy-adamantane (29%), l-bromo-3,5-dimethyladamantane (13%), 1,3-dimethoxy-5,7-dimethyladamantane (40%), l-bromo-3,5-dimethyl-7-methoxyadamantane (12%) and residual l,3-dibromo-5,7-dimethyladamantane (2%) (OV-17 125(4) 3 2 ) 200° t = 2.0, 5.5, 6.4, 7.0, 8.1 and 9.2 minutes) Again a l l compounds were i d e n t i c a l to authentic samples except f o r the bromo-ether, mp 28.5 - 29.5°. Br. )CH 3 MS - 272(trace), 193(100), 137(65), 121(60), 107(12), 105(15), 97(13), 95(13), 91(20) - 200 -IR - 1450(m), 1365(w), 1332(m), 1310(m), 1240(v), 1230(w), 1190(m), 1170(w), 1095(wsh), 1090(mb), 1080(wsh), 965(w), 935(w), 915(w), 865(m) NMR (CS 2) - s i n g l e t , 0.92, (6H), -CH3; s i n g l e t , 1.10, (2H), H 2; s i n g l e t , 1.33, (4H), H 3; s i n g l e t , 1.84, (4H), H 4; s i n g l e t , 2.07, (2H), s i n g l e t , 3.12, (6H), -0CH3 Analysis - C^H^BrO C H calculated 57.15 7.75 found 57.02 7.68 Ir r a d i a t i o n of 1,3,5-Tfibroitioadamantane A degassed solution of 150 mg (0.40 mmole) of 1,3,5-tribromoadamantane i n 70 ml of methanol was irr a d i a t e d through quartz for 21 hours (no s t a r t i n g material by g l c ) . Analysis showed the major products to be 1-methoxy-adamantane (19%), 1,3-dimethoxyadamantane (50%), and 1,3,5-trimethoxy-adamantane (22%) by comparison with authentic samples. l-ChlOrb-3-methoxyadamantane A well degassed solution of 50 mg (0.34 mmole) of l-bromo-3-chloro-adamantane i n 70 ml of methanol was i r r a d i a t e d through quartz for 17 hours. Workup as before yielded a l i g h t yellow s t i c k y s o l i d which consisted of 1-chloroadamantane (42%) and l-chloro-3-methoxyadamantane (58%) ^  mp just below room temperature). - 201 -MS - 202(5), 200(15), 171(4), 169(11), 166(13), 165(100), 143(14), 109(40), 93(16), 91(9) IR - 1448(m), 1340(m), 1320(w), 1298(m), 1192(m), 1150(w), 1110(s), 1090(s), 1044(s), 967(m), 898(s) NMR (C &H 6) - broad s i n g l e t , 1.14, (2H), H 5; broad s i n g l e t , 1.45, (4H), H 3; singlet,.1.85, (6H), H 2 + H 4; s i n g l e t , 2.18, (2H), H • s i n g l e t , 2.93, (3H), -0CH3 Analysis - C^H^CIO C H calculated 65.82 8.54 found 65.63 8.43 The same reaction with l-chloro-3-iodoadamantane i n methanol produced the chloroether as the sole product with no evidence for any 1-chloroadamantane. 2-Methoxybicyclo/^.2.x\heptane A wel l degassed solution of 520 mg (2.34 mmole) of exo-2-iodonorbornane i n 12 ml of methanol was ir r a d i a t e d through quartz for 24 hours. The dark solution was worked up as before to y i e l d a dark yellow o i l which was eluted with pentane down a short alumina column to y i e l d 240 mg (81%) of a 158 l i g h t yellow l i q u i d (extremely v o l a t i l e ) MS - Parent(126) IR - 1450(m), 1360(m), 1304(w), 1220(w), 1200(w), 1180(w), 1120(w), 1104(s), 1064(m), 982Cm), 920(w), 890(w) NMR (CC14) - mul t i p l e t s , 0.90 - 1.56, (8H); broad s i n g l e t , 2.24, (2H); broad s i n g l e t , 3.08, (1H)j s i n g l e t , 3.19, (3H) - 202 -I r r a d i a t i o n of 1^4-Diiod6bicyclo/T2. 2.ljheptane A well degassed solution of 250 mg (0.72 mmole) of 1,4-diiodonorbornane i n 15 ml of freshly d i s t i l l e d methanol was ir r a d i a t e d through quartz for 24 hours. The dark purple solution was worked up as before to y i e l d a dark yellow o i l which consisted of three components by glc i n the r e l a t i v e r a t i o of 19:43:38. The compounds were p u r i f i e d by preparative g l c . The f i r s t component was shown to be 1-methoxynorbornane. MS - 127(10), 126(100), 125(34), 111(43), 106(13), 105(13), 97(55), 94(14) IR - 1460(m), 1315(s), 1260(m), 1220(w), 1198(w), 1170(w), 1132(s), 1095(m), 1025(m), 930(w) NMR (CCl^) - m u l t i p l e t s , 0.92 - 1.80, (11H); broad s i n g l e t , 2.04, (IH); s i n g l e t , 3.15, (3H) The major product was shown to be 1,4-dimethoxynorbornane. MS - 156(16), 127(100), 125(26), 109(15), 97(23) IR - 1458(m), 1320(s), 1298(w), 1262(w), 1217(s), 1140(w), 1120(sb), 1030(s), 910 (m) NMR (CC14) - m u l t i p l e t s , 1.28 - 1.84, (10H); s i n g l e t , 3.13, (6H) The t h i r d component was found to be l-iodo-4-methoxynorbornane. MS - 252(trace), 125(100), 109(20), 97(4) IR - 1480(w), 1443(m), 1308(s), 1277(ra), 1198(s), 1140(m), 1120(m), 1037(m), 1024(m), 982(s), 950(w), 870(s) NMR (CC14) - m u l t i p l e t s , 1.50 - 2.42, (10H); s i n g l e t , 3.22, (3H) - 203 T. Analysis - CgH^OI _C_ H calculated 38.08 5.18 found 37.78 5.33 When the above reaction was repeated i n greater d i l u t i o n (eg 200 mg of diiodide i n 50 ml of methanol) only the mono and diether were observed. The above reaction was repeated with 250 mg (0.72 mmole) of the . diiodide i n 12 ml of reagent CH^ OD and worked up, after 22 hours. The same three products were observed and the monoether collected by glc and studied by mass spectrometry for the deuterium content. Calculations (see appendix) indicated a t o t a l of 17% deuterium incorporation. General Procedure for 0 o Photolytic Runs The adamantyl halides were run as d i l u t e solutions i n freshly d i s t i l l e d methanol through pyrex or quartz vessels as before, only t h i s time with oxygen gas being bubbled through the solution during the course of the reaction. The solution was worked up as before (no r e a l difference i n the length of the reaction was found) to y i e l d the crude products which were p u r i f i e d by g l c . Reaction of 1-Haloadamantanes A solution of 300 mg (1.39 mmole) of 1-bromoadamantane i n 70 ml of methanol was ir r a d i a t e d through quartz with 0^ for 16 hours. Workup as before yielded a yellow s o l i d which consisted of 1-methoxyadamantane (69%) and 1-adamantanol (31%), mp 186 - 187° ( l i t 1 8 187 - 188°) IR - 3550(w), 1450(m), 15Vr(w), 1295(w), 1110(s), 1085(s), 978(m), 930(s) NMR (CS 2) - s i n g l e t , 1.02, (IH), OH; mu l t i p l e t , 1.64, ( 1 2 H ) , ^ g ; broad s i n g l e t , 2.06, (3H), & . S i m i l a r l y , a solution of 130 mg (0.5 mmole) of 1-iodoadamantane i n 70 -ml of methanol was ir r a d i a t e d through pyrex with 0^ for 3 hours. Workup - 2 0 4 ~ as before yielded 1-methoxyadamantane (.94%) and 1-adamantanol (6%) i d e n t i c a l to authentic materials. A solution of 215 mg (1.0 mmole) of 1-bromoadamantane i n 70 ml of cyclohexane was i r r a d i a t e d through quartz with 0^ bubbling through the solution for 17 hours. Workup as before yielded a l i g h t yellow s o l i d which consisted of 1-adamantanol (32%) and residual 1-bromoadamantane (68%). Reaction of l-Br6mb-3,5-dimethylada~/iantane A solution of 350 mg (1.44 mmole) of l-bromo-3,5-dimethyladamantane i n 70 ml of methanol was ir r a d i a t e d through quartz with 0 2 bubbling through the solution for 11 hours. Workup as before yielded a yellow s o l i d containing l-methoxy-3,5-dimethyladamantane (64%) and 1,3-dimethyladamantan-5-ol (36%), mp (alcohol) 95.5 - 96.5° ( l i t 1 5 9 97°) MS - 180(49), 165(18), 149(10), 147(20), 123(100), 109(91), 107(35) IR - 3580(w), 1445(s), 1363(w), 1340(m), 1310(m), 1165(m), 1062(s), 1025(s), 975(w), 935(m), 915(m), 882(m) NMR (CgHg) - s i n g l e t , 0.60, (1H), -OH; s i n g l e t , 0.78, (6H), -CH3; s i n g l e t , 0.94, (2H), H 1: unresolved doublet, 1.13, (4H), H 2; s i n g l e t , 1.23, (4H), H 3; unresolved doublet, 1.45, (2H), H q; mu l t i p l e t , 2.01, (1H), H,_ - 205 -Reaction of 1,3-Jibfbmdadamantane A solution of 400 mg (1.36 mmole) of 1,3-dibromoadamantane i n 70 ml of methanol was irr a d i a t e d through quartz with 0^ for 17 hours. Workup as before yielded 5 products i n the r a t i o of 12:6:35:6:41. The f i r s t four products were found by comparison to authentic samples to be 1-methoxy-adamantane, 1-adamantanol, 1,3-dimethoxyadamantane and l-bromo-3-methoxy-adamantane. The major product was found to be l-methoxyadamantan-3-ol, mp 61 - 62.5°. MS - 182(34), 164(7), 151(11), 125(100), 109(16), 95(10), 93(11) IR - 3600(w), 1445(m), 1340(m), 1320(w), 1298(m), 1190(m), 1120(s), 1100(w), 1070(s), 995(s), 940(s), 885(m) NMR (CgHg) - s i n g l e t , 1.18, (1H), -OH; unresolved t r i p l e t , 1.25, (2H), H 5; unresolved doublet, 1.47, (4H), ^  or H^; unresolved doublet, 1.54, (4H), H 2 or H^; s i n g l e t , 1.65, (2H), H^ broad s i n g l e t , 2.03, (2H), H 3; s i n g l e t , 3.07, (3H), -0CH3 High Resolution MS - ^^^2 calculated 182.1306 found 182.1308 - 206 -1,1,2,2-Tetraphenyl-l.2-ethandiol The procedure of Feiser was f ollowed"1"0".' A solution of 1.5 g (8.25 mmole) of benzophenone i n 50 ml of 2-propanol with 3 drops of g l a c i a l acetic acid i n a pyrex f l a s k was stopped and allowed to s i t exposed to sunlight for three days. The white pr e c i p i t a t e was f i l t e r e d and washed with pentane mp 187 - 188° ( l i t 1 6 0 188 - 189°) IR (nujol) - 3500(w), 1320(mb), 1250(mb), 1152(mb), 1038(m), 1020(m), 950(w), 905(w), 8A0(mb), 753(s), 738(s), 696(sb) A degassed solution of 262 mg (1 mmole) of adamantyl iodide and 360 mg (2.0 mmole) of benzophenone i n 70 ml of methanol was ir r a d i a t e d through pyrex f o r 3 hours. Analysis by glc showed the products to consist of adamantane (66%) and 1-methoxyadamantane (34%). Elution with pentane down an alumina column yielded the two adamantane products. Further elution with CHC1.J yielded residual benzophenone plus a white s o l i d which was shown to be l,l,2,2-tetraphenyl-l,2-ethandiol by comparison to an authentic sample. A degassed solution of 215 mg (1 mmole) of 1-bromoadamantane and 360 mg (2 mmole) of benzophenone i n 70 ml of methanol was ir r a d i a t e d through pyrex for 20 hours. Glc indicated only residual s t a r t i n g material plus the tetraphenyl d i o l with no adamantane or adamantyl ether. The tetraphenyl d i o l was also produced by i r r a d i a t i o n of a benzophenone solution i n methanol through pyrex. - 207 -Quenching Studies A degassed solution of 262 mg (.1 mmole) of 1-iodoadamantane and 1.36 g (20.0 mmole) of a cis-trans mixture of 1,3-pentadiene i n 70 ml of methanol was i r r a d i a t e d through pyrex. The reaction was followed by glc and was 50% complete after 5 hours, 80% after 8 hours and 100% after 11 hours. In the absence of the pentadiene the reaction was finished after 2% hours. Sensitization Studies A series of solutions containing 110 mg (0.5 mmole) of 1-bromoadamantane and 3-4 mmole of a t r i p l e t s e n s i t i z e r i n 70 ml of methanol were degassed with N 2 and ir r a d i a t e d through pyrex for 12 - 18 hours. In a l l cases only s t a r t i n g material was present after workup by glc. The se n s i t i z e r s used were naphthalene,benzene, phenanthrene,<X.-chloroanthraquinone, acetophenone, 1-naphthaldehyde and fluorene. General Procedure for Photochemical N i t r i l e Reactions The desired iodide was dissolved i n either a c e t o n i t r i l e or b u t y r o n i t r i l e and two drops of water added (the reaction was slow and incomplete i f water was absent). The reaction was followed by glc arid poured into aqueous sodium b i s u l f i t e when st a r t i n g material had disappeared. To th i s was added chloroform, the layers separated and the organic phase was washed with aqueous sodium carbonate, three times with water and dried over MgSO^. Evaporation yielded the crude amide. Reaction of 1-16dbadariiaritane a)- A solution of 400 mg (1.53 mmole) of 1-iodoadamantane i n 13 ml of - 208 -a c e t o n i t r i l e (R = CH.}-) in a quartz tube was degassed we l l with N 2 and irrad i a t e d for 23 hours. Workup yielded 260 mg (88%) of a l i g h t yellow s o l i d . An a n a l y t i c a l sample was obtained by preparatiye g l c , mp 145 i-146° ( l i t 2 2 a 148°) MS - 193(81), 150(9), 136(100), 94(28) IR - 3500(w), 1685(s) , 1495 (s) , 1458Cm), 1360(m), 1340(w), 1290Cm), 1278 Cm), 1240(w), 1135(w), 1095Cw) NMR CCDC13) - broad s i n g l e t , 1.60, C6H), £ ; s i n g l e t , 1.69, C3H), -CH3; si n g l e t , 1.95, (12H),S+£; broad s i n g l e t , 3.48, (IH), -NH b) A solution of 400 mg (1.53 mmole) of 1-iodoadamantane i n 13 ml of butyronitrate (R = CH3CH2CH2~) i n a quartz tube was ir r a d i a t e d as above for 23 hours. Workup as before yielded a yellow o i l which contained some residual solvent. Elution down a short s i l i c a gel column with petroleum ether (30-60) yielded the solvent, elution with d i e t h y l ether yielded 350 mg C82%) of a l i g h t yellow s o l i d which was r e c r y s t a l l i z e d from methanol to y i e l d white c r y s t a l s , mp 118 - 119.5° C l i t 1 1 0 119 - 120°) MS - 221(65), 193(69), 164(69), 1350-00) IR - 3500(w), 1690Cs), 1500 (s) , 1457Cw), 1358Cm), 1342Cw), 1304Cw), 1290(w), 1277(w), 1202(wb), 1100(wb) IR (KBr) - 3300Cs), 1640Cs), 1540Cs) NMR CCDC13) - t r i p l e t , J = 7 Hz, 0.92, C3H), -CH3; mul t i p l e t , 1.67, (8H), -CH. + $ ; broad s i n g l e t , 2.00, (12H) , ( T ; t r i p l e t , J = 7 Hz, 0 2.06, (2H), -CH^; broad s i n g l e t , 5.10, (IH), -NH - 209 -Reaction of 2-Iddbadamantane ±02. RCN a) A solution of 200 mg (0 .77 mmole) of 2-iodoadamantane i n 13 ml of a c e t o n i t r i l e (R = CH^-) i n a quartz tube was ir r a d i a t e d as before,for 10 hours. Workup yielded 140 mg (96%) of a l i g h t yellow s o l i d . Preparative glc yielded feathery white c r y s t a l s , mp 192 - 193°. MS - 193(100) , 178(11), 1 5 0 ( 1 6 ) , 1 3 6 ( 9 ) , 135(27), 1 3 4 ( 4 9 ) , 92(31) IR (nearly insoluble i n CCl^) - 3480(w), 1680(m), 1500(m) IR (KBr) - 3 3 0 0(s), 1640(sb), 1550(sb), 14v<"(m), 1360(m), 1295(m), 1278(m), 1125(m), 960(m) NMR (CDC1 3) - mu l t i p l e t s , 1 .45 - 2 . 0 5 , (15H); s i n g l e t , 2 . 0 0 , (3H), -CH3; broad doublet, J = 7 H.3, 4 . 0 6 , (1H), H«<; broad s i n g l e t , 5 . 8 2 , (1H), -NH Analysis - c 1 2 H 1 9 N O N calculated 74 .56 9 . 9 0 7 .25 found 74.42 10 .05 7 .20 b) A solution of 135 mg (0 .52 mmole) of 2-iodoadamantane i n 14 ml of b u t y r o n i t r i l e (R - CH3CH2CH2-) i n a quartz tube was ir r a d i a t e d as before f o r 15 hours. Workup as before yielded a yellow o i l which was eluted with petroleum ether (30-60) down a short s i l i c a gel column to y i e l d 90 mg (80%) of a l i g h t yellow s o l i d . Preparative glc gave a white s o l i d , mp 145 - 1 4 6 . 5 C MS - 221(100) , 2 0 6 ( 2 6 ) , 1 9 3 ( 4 0 ) , 1 8 2 ( 2 3 ) , 1 5 0 ( 2 6 ) , 1 3 5 ( 4 5 ) , 1 3 4 ( 3 5 ) , 119(14) IR - 3470(w), 1 6 8 0(s), 1 4 9 5(s), 1468(w), 1448(w), 1190(w), 1120(w), 908(s) IR (KBr) - 3300(m), 1 6 3 5(s), 1550(s) NMR (CDC1 3) - t r i p l e t , J = 7 Hz, 0 . 9 5 , (3H), -CH3; m u l t i p l e t , 1 .28 - 2 . 0 5 , - 210 -(17H); t r i p l e t , J = 7 Hz, 2.12, (2H), CCH 2; broad doublet, J = 7 Hz, 4.05, (IH), H ; broad m u l t i p l e t , 5.72, (LH), -NH Analysis - C^H^NO C H • N c a l c u l a t e d 75.97 10.47 6.33 found 75.84 10.53 6.28 l-Acetamido-3-iodbadamarttane A w e l l degassed s o l u t i o n of 300 mg CO.77 mmole) of 1,3-diiodoadamantane i n 12 ml of f r e s h l y d i s t i l l e d CH^CN containing 2 drops of water was i r r a d i a t e d through quartz f o r 18 hours. Workup as before y i e l d e d a s t i c k y brown s o l i d which contained one major peak by g l c with a small amount of s t a r t i n g m a t e r i a l . The s o l i d was r e c r y s t a l l i z e d four times from CCl^ to y i e l d a l i g h t yellow s o l i d , mp 158.5 - 160°. MS - 319Ctrace), 192C100), 149C42), 136C42), 94C40) IR CKBr) - 3250 Cm), 3020Cw), 1645Cs) , 1550Cs), 1445 Cm), 1365 Cm), 1300 Cm), 1105Cw), 1032Cm), 995Cw), 975Cw), 930Cm), 835Cm), 760Cm) NMR CCS 2) - s i n g l e t , 1.70, C2H), H 5; s i n g l e t , 1.73, C3H), -CH 3; s i n g l e t , 1.98, C6H), H 2 + H 4, s i n g l e t , 2.43, C4H), H 3; s i n g l e t , 2.70, C2H), E± C H N calcu l a t e d 45.16 5.68 4.38 found 46.14 -5.87 3.88 calc u l a t e d 319.1877 found 319.1872 Analysis - C . J NOI High Resolution MS I r r a d i a t i o n of a s o l u t i o n of the acetamido-iodide i n CH3CN l e d to the formation of the 1,3-diamide with no evidence of the monoamide. - 211 -1,3-Diacetamiddadamaritane A well degassed solution of 250 mg (0.64 mmole) of 1,3-diiodoadamantane in 50 ml of CH^ CN containing 2 drops of water was irradiated through quartz for 18 hours. A total of 100 mg (62%) of light brown crystals were f i l t e r e d from the reaction mixture. The solution was worked up as before to yield a dark brown solid. Glc showed both fractions to consist of the same single peak. Recrystallization from CR^CN yielded 120 mg (75%) of white feathery crystals, mp 222 - 224° ( l i t 2 2 b 226 - 228°) MS - 250(67), 207(100), 193(58), 151(14), 150(15), 149(18), 148(20), 136(28), 128(46), 127(22) IR - 3450(w), 1680(s), 1495(m), 1360(w), 1328(w), 1295(w), 1270(w), 1215(w), 1122(w), 1032(w) NMR (DMS0-d6) - broad singlet, 1.50, (2H), & ; singlet, 1.74, (6H), -CH3; broad singlet, 1.84, (8H),£& ; multiplet, 2il0, (2H) , c?" ; singlet, 2.15, (2H),£ . Reaction of "xo-2-i6d6bicyclo£2;2;Qheptane a) A solution of 400 mg (1.80 mmole) of exo-2-iodonorbornane in 12 ml of acetonitrile (R = CH^-) in a quartz tube was irradiated for 23 hours. Workup yielded an orange solid which consisted of nearly equal amounts of - 212 -s t a r t i n g material and product. Low temperature r e c r y s t a l l i z a t i o n from pentane yielded a l i g h t yellow s o l i d . ' Preparative glc gave a white s o l i d , mp 132 - 134° ( l i t 1 6 1 132 - 133°), MS - 153(100), 138(12), 125(7), 124(23), 110(28), 96(11), 94(100) IR - 3400(w), 1685(s), 1500(s), 1120(m), 910(s) IR (KBr) - 3300(s), 1640(s), 1540(s) NMR (CDC1 3) - multiplet, 1.10 - 2.00, (8H); s i n g l e t , 1.92, (3H), -CH3; broad s i n g l e t , 2.23, (2H), bridgeheads; mul t i p l e t , 3.70, (1H), H<<; broad s i n g l e t , 5.40, (1H), -NH b) A solution of 500 mg (2.25 mmole) of exo-2-iodonorbornane i n 12 ml of b u t y r o n i t r i l e (R = CHgC^CH^) i n a quartz tube was i r r a d i a t e d for 23 hours to y i e l d an equimixture of product and st a r t i n g material. Elution with petroleum ether down a s i l i c a gel column yielded s t a r t i n g material plus solvent; elution with chloroform yielded the crude amide. Preparative glc yielded a white s o l i d , mp 73.5 - 75°. MS - 181(100), 166(9), 153(23), 152(27), 137(16), 110(54), 109(25), 94(50) IR - 3400(w), 1680(s), 1490(s), 910(s) IR (KBr) - 3300(s), 1640(s), 1540(s) NMR (CDC1J - t r i p l e t , J = 7 Hz, 0.80, (3H), -CH.,; mu l t i p l e t s , 1.05 - 1.90, 0 (10H); t r i p l e t , J = 7 Hz, 1.96, (2H), -CCH^ broad s i n g l e t , 2.11, (2H), bridgeheads; mul t i p l e t , 3.59, (1H), Hot; broad s i n g l e t , 5.23, (1H), -NH Analysis - C J J O C H • N calculated 72.88 10.56 7.72 found 72.78 10.40 7.54 - 213 -Reaction of 1,4-Diibdbbicyclb£2.2.J heptane a) A solution of 400 mg (1.15 mmole) of 1,4-diiodonorbornane i n 13 ml of a c e t o n i t r i l e i n a quartz tube was ir r a d i a t e d for 24 hours. Workup yielded a dark o i l which consisted of two products i n a 25;75 r a t i o . Preparative glc gave a n a l y t i c a l samples of the two products (5% Carbowax 195°, t = 5 and 35 minutes). The minor product was a feathery white s o l i d which was shown to be the bridgehead amide, mp 158 - 159.5°. MS - 153(35), 138(2), 125(10), 124(100), 110(12), 96(7), 94(4) IR - 3450(w), 1685(s), 1500(m), 1360(m), 1323(w), 1302(w), 1260(wb), 910(m) IR (KBr) - 3300(m), 1650(s), 1545(s) NMR (CDCLj) - mu l t i p l e t s , 1.20 - 1.90, (10H); s i n g l e t , 1.90, (3H), -CHy, broad s i n g l e t , 2.13, (1H), bridgehead; broad s i n g l e t , 5.86, (1H), -NH Analysis - C gH 1 5N0 _C_ _H_ N calculated 70.72 9.81 9.09 found 70.67 9.80 8.96 The major product, a white s o l i d , was shown to be the iodo-acetamide, mp 96 - 98°. MS - 279(trace), 152(74), 124(4), 110(100) IR - 3360(w), 1685(s), 1495(s), 1458(w), 1360(m), 1320(m), 1290(m), 1265(m), 1202(m), 985(sb), 910(m), 875(wb), IR (KBr) - 3300(m), 1635(s), 1550(s) - 214 -NMR (CDC13) - m u l t i p l e s , : 1.60 - 2.40, (10H); s i n g l e t , .1.90, (3H) , -CH3; broad s i n g l e t , 5.77, ClH), -NH. Analysis - CgH^NOI C H N calculated 38.72 5.05 5.01 found 39.00 4.98 4.80 b) A solution of 315 mg (.0.91 mmole) of 1,4-diiodonorbornane i n 15 ml of b u t y r o n i t r i l e (R = CH^CH^CH^-) i n a quartz tube was irr a d i a t e d for 24 hours. Workup as before yielded a thick o i l which contained two components i n a 40:60 r a t i o . Preparative glc yielded the two compounds (5% Carbowax 220°, t = 2.5, 17 minutes). The minor product was shown to be the bridgehead amide, mp 91 - 92.5°. MS - 181(44), 166(3), 153(12), 152(100), 137(4), 110(32), 109(13), 94(12) IR - 3350(w), 1685(s), 1495(s), 1325(m), 1300(w), 1260(w), 1190(w) IR (KBr) - 3300(m), 1640(s), 1550(s) NMR (CDC13) - t r i p l e t , J = 7 Hz, 0.93, (3H), -CH3; mult i p l e t s , 1.20 - 1.90, (12H); t r i p l e t , J = 7 Hz, 2,11, (2H),C-CH2; broad s i n g l e t , 2.15, (IH), bridgehead; broad s i n g l e t , 5.62, (IH), -NH Analysis - C^H^NO _C_ _H_ N calculated 72.88 10.56 7.72 found 72.75 10.57 7.53 The major component was shown to be the iodo-amide, mp 103 - 104.5°. MS - 307(trace), 180(48), 152(4), 110(100) IR - 3350(w), 1685(s), 1495(s), 1325(ra), 1285(w), 1210(m), 1000(m) IR (KBr) - 3300(m), 1640(s), 1550(s) NMR (CDC13) - t r i p l e t , J = 7 Hz, 0.91, (3H), -CH3; mu l t i p l e t s , 1.20 - 2.30, (14H); t r i p l e t , J = 7 Hz, 2.10, (2H>, -C-CH2; broad s i n g l e t , 5.52, (IH), -NH - 215 -Analysis - C . ^ H ^ N O I C H N calculated 43.01 5.90 4.56 found 42.73 5.70 4.70 Photochemistry i n Halogenated Solvents A solution of adamantane i n a chlorinated solvent was degassed well with N 2 and then ir r a d i a t e d through quartz for 50 hours. No reaction at a l l was observed when methylene chloride -ras the solvent, while i n chloroform a 30% y i e l d of 1-chloroadamantane and a 2% y i e l d of the 2-chloride was observed. In carbon tetrachloride both mono and dichlorinated products were observed as w e l l as hexachloroethane. To avoid the problem of separating secondary monochlorides a series of monohaloadamantanes were used. The reaction mixture from the i r r a d i a t i o n of a solution of 1-chloro-adamantane i n carbon tetrachloride was poured into aqueous sodium bicarbonate and separated. The organic phase was washed wel l with water and dried over magnesium sulfate. Evaporation yielded a yellow s o l i d which was eluted down a short s i l i c a gel column with petroleum ether (30-60). The f i r s t fractions yielded hexachloroethane. The chlorides were washed off with chloroform and rechromatographed down an alumina column with petroleum ether (30-60). A n a l y t i c a l samples were obtained by preparative g l c . The products were found to be 1,3-dichloroadamantane, anti-1,4-dichloro-adamantane, syn-1,4-dichloroadamantane, and 1,3,5-trichloroadamantane i n order of elution. The bridgehead chlorides were the major products and a l l four compounds were i d e n t i c a l i n a l l respects to authentic samples. Reaction of l-Brbmoadamantane A degassed solution of 1-bromoadamantane i n carbon tetrachloride was irr a d i a t e d through quartz for 50 yours. Workup and column chromatography as before yielded four major products. - 216 -The f i r s t one was shown to be l-bromo-3-chloroadamantane, mp 101.5 103 . MS - 248(trace), 171(33), 169(100), 113(4), 111(9), 103(8), 93(10), 91(17) IR - 1450(s), 1338(s), 1318(s), 1284(.s), ll00(w), 1024(s), 1006(H), 958(m), 940(w), 840(s), 713(m), 675(m) NMR (C 6H 6) - unresolved t r i p l e t , 1.05, (2H), H 5; broad s i n g l e t , 1.61, (2H), H 4; doublet, 1.74, (4H), H 3; doublet, 1.88,°(4H), H 2; s i n g l e t , 2.55, (2H), H x Analysis - C. H BrCl The second and t h i r d products were the syn and a n t i isomers of l-bromo-4-chloroadamantane which could not be separated. MS - 248(trace), 205(3), 203(6), 171(32), 169(100), 133(22), 105(9), 93(8), 91(19) IR - 1445(s), 1342(m), 1285(m), 1260(m), 1100(w), 1025(s), 972(w), 942(m), 922(m), 685(m) NMR (CCl^) - multiplets, 1.80 - 2.95; s i n g l e t , 4.20, (1H), syn; s i n g l e t , 4.36, (0.2H), a n t i - 217 -C H 48.14 5,65 47.85 5.50 The fourth product was shown to be l-bromo-3,5-dichloroadamantane, mp 104.5 - 106°. MS - 282(trace), 205(33), 203(100), 171(8), 169(16), 167(14), 127(19), 91(22) IR - 1450(s), 1342(w), 1330(w), 1311(s), 1280(m), 1225(w), 1132(w), 1030(s), 960(m), 854(s), 838(m) NMR (CCl^) - unresolved doublet, 2.02, (4H), H 3; unresolved doublet, 2.16, (2H), H 5; mu l t i p l e t , 2.36, (IH), H 4; s i n g l e t , 2.42, (2H), .H1; s i n g l e t , 2.56, (4H), H 2 Analysis - C ^ H ^ B r C ^ C H calculated 42.29 4.61 found 42.20 4.70 Reaction of l-Fluofoadamaritane The same photolytic reaction was done using 1-fluoroadamantane i n carbon tetrachloride and the products i s o l a t e d as before. The f i r s t one off the column was shown to be l-chloro-3-fluoroadamantane, mp 177 - 178°. Analysis - C ^ H ^ B r C l calculated found - 218 -MS - 190(2), 188(4), 153(100), 123(31), 103(19), 105(24), 97(16) IR - 1448(s), 1348(m), 1340(s), 1320(s), 1295(s), 1150(w), 1105(s), 1078(s), 1037(w), 967(s), 944(m), 920(s), 910(w), 844(m), 684(mb) NMR (CC14) - unresolved t r i p l e t , 1.55, (2H) , H,.; m u l t i p l e t , 1.81, (4H), H 2; unresolved doublet, 2.01, (4H), H 3; doublet, J = 5.5 Hz, 2.23 (2H), H^ broad s i n g l e t , 2.35, (2H), H^ NMR ( 1 9F) - s i n g l e t , -133.0, SCS -5.0 Analysis - C ^ H ^ F C l _C_ H calculated 63.66 7.48 found 63.66 7.69 The second product was anti-4-chloro-l-fluoroadamantane, mp 207 - 208°. m - 190(9), 188(21), 153(29), 152(100), 110(21), 97(42), IR - 1445(s), 1360(w), 1350(s), 1300(w), 1280(m), 1262(w), 1218(m), 1180(w), 1102(s), 1090(s), 1060(s), 960(s), 925(w), 918(s) NMR (CC14) - multiplets, 1.45 - 2.00, (8H); multiplets, 2.05 - 2.58, (5H); s i n g l e t , 4.09, (1H); NMR ( 1 9F) - s i n g l e t , -132.4, SCS, -4.4 High Resolution MS - C ^ H ^ F C l calculated 188.0767 found 188.0766 - 219 -The t h i r d product was shown to be syn-4-chloro-l-fluoroadamantane, mp 213 - 215.5° (sub). MS - 190(12), 188(27), 153(25), 152(100), 110(48), 97(53) IR - 1450(s), 1360(w), 1342(m), 1320(w), 1298(w), 1280(w), 1214(m), 1110(s), 1100(w), 1080(s), 1060(.w), 982(s), 964(w), 940(w), 930(s) NMR (CCl^) - multiplets, 1.40 - 2.45, (13H); broad s i n g l e t , 4.18, (IH) NMR ( 1 9F) - s i n g l e t , -137.2, SCS -9.2 High Resolution MS - C ^ H ^ F C l calculated 188.0767 found 188.0765 The fourth product was shown to be 1,3-dichloro-5-fluoroadamantane, mp 135.5 - 137°. MS - 224(6), 222(12), 189(34), 187(100), 151(8), 131(14), 97(11), 91(8) IR - 1444(s), 1342(m), 1318(s), 1282(s), 1230(m), 1130(m), 1092(s), 1014(m), 930 ( s ) , 855(s) NMR (CC14) - t r i p l e t , J = 3.5 Hz, 1.80, (2H), H 5; s i n g l e t , 1.93, (4H), H 3; doublet, J = 5.5 Hz, 2.20, (4H), H 2; s i n g l e t , 2.39, (2H), U ; m u l t i p l e t , 2.47, (IH), NMR ( 1 9F) - s i n g l e t , -136.4, SCS -8.4 Analysis - ^ 1 Q \ 3 ^ 2 — — calculated 53.83 5.87 found 53.50 5.99 - 220 -Reaction of l-Ibdoadamaritane In contrast to the other h a l i d e s , i r r a d i a t i o n of a carbon t e t r a c h l o r i d e s o l u t i o n of 1-iodoadamantane d i d not lead to free r a d i c a l c h l o r i n a t i o n . A f t e r 4 hours the iodide had been consumed y i e l d i n g a dark purple s o l u t i o n . Workup as before y i e l d e d a dark yellow s o l i d shown to consist of mainly 1-chloroadamantane with a small amount of 1,3-dichloroadamantane present. When a l l the above reactions were repeated using bromotrichloromethane as the solvent only the bridgehead bromides were formed with no production of any hexachloroethane being observed. There was also no evidence f o r any c h l o r i n a t i o n products. From the r e a c t i o n of 1-fluoroadamantane, two products were observed ( i n a d d i t i o n to 25% r e s i d u a l s t a r t i n g m a t e r i a l ) . *< Hi The major product was shown to be l-bromo-3-fluoroadamantane, mp 136 -137°. •MS - 232(trace), 153(100), 133(9), 111(7), 105(5), 99(5), 97(15), 93(13), 91(7) IR - 1445(B), 1356(m), 1338(s), 1318(s), 1290(s), 1270(w), 1150(w), 1102(s), 1077(s), 962(s), 942(w), 920(s), 678(m) NMR (C 6H 6) - unresolved t r i p l e t , 1.05, (2H), H 5; m u l t i p l e t , 1.58, (4H), H 3; broad s i n g l e t , 1.72, (2H), H 4; broad s i n g l e t , 1.91, (4H), H 2; doublet, J = 5.5 Hz, 2.40, (2H), Hj NMR ( 1 9 F ) - s i n g l e t , -131.6, SCS -3.6 "Analysis - C ^ H ^ F B r _C_ _H_ c a l c u l a t e d 51.52 6.05 found 51.44 6.17 - 221 -The minor product was found to be l,3-dibromo-5-fluoroadamantane, mp 160 - 163.0°. MS - 310(trace), 233(94), 231(100), 187(9), 151(22), 131(7), 111(11), 109(9), 97(9), 91(11) IR - 1450(m), 1350(w), 1318(s), 1282(m), 1230(w), 1092(m), 1010(w), 965(m), 926(s), 710(w) NMR (C 6H 6) - mul t i p l e t , 1.32, (2H), H^; mul t i p l e t , 1.47, (1H), H 5; broad s i n g l e t , 1.58, (4H), H 3; doublet, J = 5.5 Hz, 2.13, (4H), H 2; s i n g l e t , 2.44, (2H), H x  NMR ( 1 9F) - s i n g l e t , -133.2, SCS -5.2 High Resolution MS - Cj^gH^F 6^ calculated 309.9369 found 309.9351 Reaction of 1-Chloroadamaritane The photolysis of 1-chloroadamantane i n BrCCl^ produced two main products which were collected by g l c . The major product was shown to be l-bromo-3-chloroadamantane, i d e n t i c a l i n a l l respects to that produced by the photolysis of 1-bromoadamantane i n carbon tetrachloride. The minor product was shown to be l-chloro-3,5-dibromoadamantane, mp 98 - 102°. - 222 -MS - 328(trace), 251(29), 249(100), 247(77), 169(13), 167(19), 133(8), 132(8), 131(15), 91(25) IR - 1455(m), 13^2(w), 1325(w), 1310(s), 1281(m), 1028(s), 960(m), 850(s), 710(m) NMR (CgHg) - singlet, 1.45, (3H), H 4 + H5; unresolved doublet., 1.59, (4H), H3; singlet, 2.27, (4H), H2; singlet, 2.42, (2H), Hj High Resolution MS - C ^ H ^ B ^ C l 81 no parent c , r . H n B r C 1 calculated 248.9869 Reaction of l-Bromoadamantane Two products were observed from the i r r a d i a t i o n of 1-bromoadamantane i n BrCCl 3. These were collected by glc and shown to be 1,3-dibromoadamantane and 1,3,5-tribromoadamantane. Reaction of 1-Iodoadamaritane A wel l degassed solution of 1-iodoadamantane i n BrCCl 3 was ir r a d i a t e d through quartz for 4 hours. The dark purple solution was worked up as before to y i e l d a dark yellow solution which consisted mainly of 1-bromoadamantane with small amounts of 1-chloroadamantane and 1,3-dibromoadamantane. Reaction of 1,3-dimethy1-5-fluoroadamantane i n CC1, A well degassed solution of 450 mg (2.47 mmole) of 1,3-dimethyl-5-fluoroadamantane i n 20 ml of reagent CCl^ was ir r a d i a t e d through quartz for 12 hours. P u r i f i c a t i o n and removal of hexachloroethane by column chrom-atography as before yielded the crude products which were p u r i f i e d by gl c . found 248.9874 - 223 -The major product was shown to be l-chloro-3,5-dimethyl-7-fluoroadamantane, mp just below room temperature. MS - 218(11), 216(28), 181(100), 180(30), 167(13), 165(13), 125(87), 111(48), 91(20) IR - 1445(s), 1365(w), 1358(m), 1238(w), 1180(m), 1038(s), 980(m), 938(w), 915(m), 882(s), 840(w), 675 (m) NMR (CgHg) - s i n g l e t , 0.61, C6H), -CI^; s i n g l e t , 0.87, (2H), H^; doublet, J = 5.5 Hz, 1.27, (4H), H 2; s i n g l e t , 1.45, (4H), H 3; doublet, J = 5.5 Hz, 2.10, (2H), H i ;  NMR ( 1 9F) - s i n g l e t , -137.0, SCS -9.0 High Resolution MS - C ^ H ^ F C l calculated 216.1080 found 216.1067 Two minor products ( o i l s ) were also collected by glc but nmr showed them to each contain three dif f e r e n t methyl resonances. They were not characterized further. Reaction of 1,3-Dimethyl-5-fluofbadamarttane i n BfCCl^ A we l l degassed solution of 500 mg (2.74 mmole) of 1,3-dimethyl-5-fluoroadamantane i n 8 ml of BrCCl-j was i r r a d i a t e d through quartz for 6 hours. Workup as before followed by column chromatography yielded residual s t a r t i n g material (46%) and the brominated species which were collected by glc. The major product was shown to be l-bromo-3,5-dimethyl-7-fluoroadamantane, mp 31 - 32°. MS - 262(2), 260(2), 181(100), 167(17), 161(10), 125(45), 121(25), 119(64), 117(62) - 224 -IR - 1445(s), 1365(w), 1328(s), 1310(s), 1282(w), 1240(m), 1180(s), 1032(s), 1002(w), 978(m), 932(m) , 913(m), 878(s) NMR (C 6H 6) - s i n g l e t , 0.58, (6H) , -CE 3; s i n g l e t , 0.88, (2H), H^; doublet, J = 5.5 Hz, 1.28, (4H), H 3; s i n g l e t , 1.62, (4H), H 2; doublet, J = 5.5 Hz, 2.27, (2H), K •. i q NMR ( F) - s i n g l e t , -135.9, SCS -7.9 High Resolution MS - C 1 2H 1 8FBr calculated 261.1806 found 261.1803 Two minor products ( o i l s ) were also collected by glc but nmr showed them to contain three different methyl resonances. They were not characterized further. Reaction of 1-Cyanoadamantane i n BrCCl. A we l l degassed solution of 500 mg (3.10 mmole) of 1-cyanoadamantane (Aldrich) i n 20 ml of BrCClj was i r r a d i a t e d through quartz for 24 hours. Workup as before followed by alumina column chromatography (30-60 petroleum ether) yielded 360 mg (48%) of a l i g h t yellow s o l i d . R e c r y s t a l l i z a t i o n from hexane produced white p l a t e l e t s , mp 128.5 - 130°. MS - no parent, 160(100), 133(16), 118(13), 104(22), 91(19) IR - 2240(w), 1445(s), 1370(w), 1357(w), 1340(w), 1335(w), 1320(w), 1300(m), 1238(w), 1220(m), 1100(w), 1090(w), 998(w), 963(s), 942(w), 900(s), 678(m) NMR (C 6H 6) - s i n g l e t , 1.00, (2H), H 5; s i n g l e t , 1.38, (6H), H 3 + H^; s i n g l e t , 1.82, (4H), H 2; s i n g l e t , 2.18, (2H), Hj - 225 -Analysis - C 1 1H 1 /BrN 11 14 C H N calculated 55.02 5.87 5.83 found 55.02 5.90 5.80 l-Cyarib-3-f luorbadamaritane To a solution of 130 mg (0.54 mmole) of l-bromo-3-cyanoadamantane i n 20 ml of cyclohexane was added 450 mg (3.56 mmole) of AgE. The solution was s t i r r e d under re f l u x for 2 hours. The solution was then f i l t e r e d and evaporated to y i e l d a l i g h t yellow s o l i d . Elution with 30-60 petroleum ether down an alumina column yielded 86 mg (88%) of a f l u f f y white s o l i d , mp 180 - 182.5°. MS - 179(44), 160(trace), 152(100), 111(59), 97(33), 93(22), 91(26) IR - 2245(w), I452(s), 1350(m), 1330(m), 1318(m), 1285(w), 1258(w), 1135(s), 1018(s), 950(w), 940(m), 883(m) NMR (C 6H 6) - mu l t i p l e t , 0.96, (2H), H 5; s i n g l e t , 1.35, (4H), H 3; doublet, J = 5.5 Hz, 1.47, (4H), H 2; broad s i n g l e t , 1.58, (2H), H 4; doublet, J = 5.5 Hz, 1.81, (2H), Hj High Resolution MS - C^H^FN calculated 179.1109 found 179.1113 - 226 « I r r a d i a t i o n i r i Amine Solvents a) Diethylamine A degassed solution of 750 mg (2.86 mmole) of 1-iodoadamantane i n 70 ml of diethylamine was i r r a d i a t e d through quartz for 2 hours. The greenish yellow solution was washed with aqueous sodium carbonate. Chloroform was added, the layers separated and the organic phase washed with water. After drying the solution was evaporated to y i e l d a l i g h t orange s o l i d which was eluted with petroleum ether (30-60) down a short alumina column to y i e l d 310 mg (80%) of a white s o l i d which was shown to be adamantane. Further e l u t i o n with chloroform yielded a s t i c k y orange s o l i d which was shown to be an adduct of adamantane with solvent. MS - 207(26), 192(47), 172(20), 150(100), 135(67), 113(15), 100(50) IR - 3400(m), 1645(m), 1450(m), 1418(w), 1378(m), 1300(w), 1260(m)', 1200(w), 1080(w), 905(w) NMR (CDC13) - t r i p l e t , J = 7 Hz, 0.97, (3H); doublet, J = 7 Hz, 1.14, (3H); unresolved t r i p l e t , 1.53, (6H), £ ; unresolved doublet, 1.72, (6H),^3 ; broad s i n g l e t , 1.95, OH),"^ ; quartet, J = 7 Hz, 2.57, (1H); quartet, J = 7 Hz, 3.03, (2H) High 'Resolution MS - C^H^N calculated 207.1986 found 207.1982 The above reaction was repeated with 500 mg (1.91 mmole) of the adamantyl iodide i n 70 ml of diethylamine with 0^ bubbling through the solution. The reaction was worked up as before after 3 hours to y i e l d a l i g h t yellow s o l i d . - 227 -Collection by glc yielded a white s o l i d i d e n t i c a l i n a l l respects to adamantanol as the only product. The same reaction was repeated with 300 mg (1.15 mmole) of adamantyl iodide plus 350 mg (1.59 mmole) of 3,5-di-t-butyl-4-hydroxytoluene i n 70 ml of diethylamine. The solution was degassed well with N 2 and irradiated through quartz. The reaction was followed by glc and was markedly slower than i n the absence of the cresol. The iodide was 60% reacted after 4 hours, 80% after 6 hours and 100% after 9 hours. Workup as before yielded a l i g h t yellow s o l i d which was shown to consist of the cresol and adamantane with no trace of the free r a d i c a l adduct. b) Triethylamine J112. N E t 3 A degassed solution of 400 mg (1.53 mmole) of 1-iodoadamantane i n 70 ml of triethylamine was ir r a d i a t e d through pyrex f o r 15 minutes. The iodide was a l l gone and the l i g h t greenish solution contained a f l u f f y white precipitate which was f i l t e r e d and washed with pentane. The solution was worked up as before and the yellow s o l i d eluted down a short alumina column with pentane to y i e l d 188 mg (92%) of adamantane. The white p r e c i p i t a t e was shown to be the hydrogen iodide s a l t of the solvent. IR (KBr) - 3000(s), 1460(s), 1420(m), 1390(m), 1360(w), 1184(w), 1162(s), 1062(w), 1034(s), 948(m), 803(m), 750(w) The above IR was very s i m i l a r to the HC1 and HBr s a l t s of triethylamine from the Sadtler Index. The above reaction was repeated with 150 mg (0.57 mmole) of adamantyl - 228 -iodide with 600 mg (2.72 mmole) of 3,5-di-t-butyl-4-hydroxytoluene i n 70 ml of triethylamine. The solution was degassed well with N 2 and irr a d i a t e d through pyrex as before. This time the reaction was complete after 6 hours. Again, the only products produced were adamantane and the hydrogen iodide s a l t of the solvent, c) Morpholine H A degassed solution of 525 mg (2.0 mmole) of adamantyl iodide i n 70 ml of morpholine was irr a d i a t e d through quartz. The s t a r t i n g material was consumed after 1 hour and the reaction worked up to y i e l d a st i c k y orange s o l i d . This was eluted with petroleum ether (30-60) down an alumina column to y i e l d 122 mg (46%) of adamantane. Further elution with chloroform yielded a l i g h t pink s o l i d which was r e c r y s t a l l i z e d from CCl^, mp 288 - 289° (dec) ( l i t 1 6 2 292°) IR (KBr) - 3400(m), 2435(w), 1630(m), 1555(m), 1443(m), 1420(m), 1342(w), 1300(m), 1220(m), 1182(w), 1095 ( s ) , 1042(m), 895 ( s ) , 870(s), 822(w) NMR (CCl^) - unresolved doublet, 1.65, (12R),ptS ; broad s i n g l e t , 2.08, (3H) ?J- ; m u l t i p l e t , 2.55, (4H); mu l t i p l e t , 3.57, (4H) The above amine was i d e n t i c a l to the product produced by the reaction of adamantyl iodide i n refluxing morpholine for 60 hours. - 229 -d) P y r r o l i d i n e A degassed solution of 420 mg (1.60 mmole) of adamantyl iodide i n 70 ml of p y r r o l i d i n e was i r r a d i a t e d through pyrex for 3 hours. Workup as before yielded a l i g h t yellow s o l i d which consisted of only adamantane by glc analysis. - 230 -BIBLIOGRAPHY 1. P.D. B a r t l e t t , L.H. Knox, J. Amer .Chem. S o c , 61, 3184 (1939). 2. a) D.E. Applequist, J.D. Roberts, Chem. Rev., 54, 1065 (1965). b) U. Scholkopf, Angew. Chem., 72, 147 (1960). c) R.C. Fort, P. von Schleyer, Advances i n A l c y c l i c Chemistry,.1, 283, (1966). d) R.C. Fort, Carbonium Ions, 4_, 1783 (1973). 3. a) J.W. Linnett, A.J. Poe, Trans. Faraday Soc.,47, 1033 (1951). b) K.B. Wiberg, J.Amer.Chem. S o c , 90, 59 (1968). c) R. Sustmann, J.E. Williams, L.C. Al l e n and P. von Schleyer, J.Amer.Chem. S o c , 91; 1037, (1969). d) R. Sustmann, J.E. Williams, M.J. Dewar, L.C. A l l e n , and P. von Schleyer, J. Amer. Chem. S o c , 91, 5350 (1969). e) W.A. Lathan, W.J. Hehne and J.A. Pople, J.Amer.Chem. S o c , 93, 808, 6377 (1971). 4. a) G.A. Olah, M.B. Comlsarow, J .Amer.Chem. Soc., 88, 1818 (1966). b) V.A. Koptyug, I.S. Isaev and A.I. Rezvuklin,Tetrahedron L e t t . T 823 (1967) 5. a) G.A. Olah, E.B. Baker, J.C. Evans, W.S. Tolgyesi, J.S. Mclntyne, and I . J . Bastien, J.Amer. Chem. S o c , 86, 1360 (1964). b) G.A. Olah, J.R. December, A. Commeyras and J.L. Bribes, J . Amer.  Chem. S o c . 93, 459 (1971). 6. R.C. Bingham, P. von Schleyer, J.Amer. Chem. S o c , 93, 3189 (1971). 7. A. Streitwieser,"Solvolytic Displacement Reactions", McGraw-Hill, N.Y., Chapter 1, 1963. 8. W. Parker, R.C. Tanner, C.I. Watt, L.W. Chang and P. von Schleyer, . J.Amer.Chem. Soc.,96, 7121 (1974). - 231 -9- C.F. Wilcox, J.G. Zajacek, J . Org. Chem., 29, 2207 (1964). 10. R.L. B i x l e r , C. Niemann, J. Org. Chem., 23, 742 (1958). 11. J.C. Kauer, U.S. Patent 3,255,254, Chem.Abstr.,65, 15249 (1966). 12. E. Osawa, Tetrahedron Lett., 115 (1974). 13. P. von Schleyer, P.R.Isele, R.C. Bingham, J. Org. Chem., 33, 1239 (1968). 14. N. Takaishi, Y. Fujikura, Y. Inamoto, H.- Ikeda and K. Aigami, Chem.Commun..371, (1975). 15. S. Landa and S. Hala, C o l l . Czech. Chem. Comm., 24, 93 (1959). 16. T.M. Grund, N. Nomura, V.Z. Williams and P. von Schleyer, Tetrahedron L e t t . . 4875 (1970). 17. A. Karim, M.A. McKervey, E.M. Engler, P. von Schleyer. Tetrahedron L e t t . . 3987, (1971). 18. P. von Schleyer, R.D. Nicholas, J.Amer.Chem. Soc.,83, 2700 (1961). 19. R.C. Fort and P. von Schleyer, J . Org. Chem.,30, 789 (1965). 20. F.N. Stepanov, V.I. Grebrodolskii, Zh. Org. Khim., 2, 1633 (1966) Chem.Abstr..66, 1153552. 21. M.R. Peterson, G.H. Wahl, Chem.Commun..1552 (1968). 22. a) H. Stetter, M. Schwartz and A. Hirschhom, Chem. Ber., 1629 (1959). b) H. Stetter and C. Wulff, Chem. Ber., 93, 1366, (I960)'. c) G.L. Baughman, J. Org. Chem., 29, 238 (1964). d) E.R. Talaty, A.E. Cancienne, A.E. Duprey, J. Chem. Soc. C , 1902 (1968) . 23. G.A. Olah and J. Welch, Synthesis, 653 (1974). 24. H. Stetter , M. Krause and W.D. Last, Chem. Ber., 102, 3357 (1969). 25. Y. Inamoto, T. Kadono and N. Taka-ishi, Syn. Comm., 2» !47 (1973). 26. M.A. McKervey, D. Grant and H. Hamill, Tetrahedron Lett .. 1975 (1970). 27.. F. Blaney, D.E. Johnston, M.A. McKervey and J . J . Rooney, Tetrahedron Lett.. 99 (1975). - 232 -28. A.C. Udding, J . Strat i n g , and H. Wynberg,Tetrahedron Lett . . 1345-(1968). 29. A.C. Udding, J . Strat i n g , H. Wynberg, and J.L. Schlatmann, Chem. Commun..657 (1966). 30. a) R.E. pincock and E.J. Torupka, J.Amer.Chem. S o c , 91, 4593, (1969). b) R.E. Pincock, J . Schmidt, W.B. Scott and E.J. Torupka, Can. J . Chem., 50, 3958 (1972). c) W.B. Scott and R.E. Pincock, J.Amer.Chem. S o c , 95, 2040 (1973). 31. R.E. Pincock, W.B. Scott and E.J. Torupka, U.S. Patent 3,649,702 32. H.W. Geluk, Synthesis, 652 (1970). 33. K.H. Yang, K. Kimoto and M. Kawanisi, B u l l . Chem. Soc. Japan, 45, 2217 (1972). 34. B.D. Cuddy, D. Grant, A. Karim, M.A. McKervey and E.J. Rea, J.C.S. Perkin I . 2701 (1972). 35. W.H.Lunn, J. Chem. Soc. C., 2124 (1970). 36. B.D. Cuddy, D. Grant, M.A. McKervey, J. Chem. Soc. C , 3173 (1971). 37. D. Grant, M.A. McKervey, J . J . Rooney, N.G. Samman, and G. Step, Chem. Commun... 1186 (1972). 38. a) A. Roldig, Methoder der Organischen Chemie. vp; Vol. V/4, p 595, (1960). b) W.K. Musgrave, "Rodd's Chemistry of Carbon Compounds", v o l . IA, p. 482, (1964). 39. H. Fi n k e l s t e i n , Chem. Ber., 43. 1528 (1910). 40. E.D. Hughes, C.K. Ingold and J.D. Mackle, J . Chem. S o c , 3173, 3177, 3187 (1955). 41. M. Schirwand H. Besendorf, Arch. Pharm., 280, 64 (1942). 42. CR. Eck, G.L. Hodgson, D.F. McSweeney, R.W. M i l l s , and T. Money, * J.C.S. Perkin I , 1938 (1974). -233-43. D. Lenoir, Tetrahedron L e t t . , 4049 (1972). 44. J.A. M i l l e r and M.J. Nunn, Tetrahedron L e t t . , 4049 (1974). 45. J.A. Vlda. Tetrahedron'Lett. t 3447 (1970). 46. J.S. F i l i p p o , A. Sowinski and L.J. Romano, J . Org. Chem., 40, 3295 (1975). 47. J.C. Kauer, A.C.S. Meeting, Houston, 1970. 48. J. Thiele and W. Peter, Ann., 369, 149 (1909). 49. F.L. Pattison and J . J . Roman, J.Amer. Chem. S o c , 79, 2311 (1957). 50. K.S. Bhandari and R.E. Pincock, Synthesis, 655 (1974). 51. P. Muller, Chem.Commun.. 895 (1973). 52. J.W. McKinley, R.E. Pincock and W.B. Scott, J Amer. Chem. S o c , 95, 2030 (1973). ' 53. G.W. Smith and H.D. Williams, J . Org. Chem., 26, 2207 (1961). 54. I . Tabushi, J . Hamuro and R. Oda, J . Org. Chem., 33, 2108(1968). 55. I . Tabushi, Y. Aoyama, S. Kujo, J . Hamuro and Z. Yoshida, J.Amer.chem. S o c , 94, 1177 (1972). 56. I . Tabushi, J . Hamura, R. Oda, J .Amer. Chem. S o c , 89, 7127 (1967). 57. F.W. Baker, H.D. Holtz and L.M. Stock. J . Org. Chem., 28, 514 (1963). 58. C.V. Smith, and W.E. B i l l u p s . J. Amer .Chem. S o c , 96, 4307 (1974). 59. I . Tabushi, Z. Yoshida and N. Takahashi. J.Amer. Chem. S o c , 92, 6670 (1970). 60. I . Tabushi, S. Kujo and Z. Yoshida, Tetrahedron L e t t . T 2329 (1973). 61. I . Tabushi, S. Kujo, P. von Schleyer, T.M. Grund, Chem,CommuiuT591 (1974). 62. D.S. Breslow, E.I. Edwards, R. Leone, P. von Schleyer, J . Amer .Chem S o c , 90, 7097 (1968). 63. P.H. Owens, G.J. Gleicher, L.M. Smith. J.Amer.Chem. S o c , 90, 4122 (1968). 64. G.J. Gleicher, J.L. Jackson, P.H. Owens, J.D. Unruth,Tetrahedron L e t t . f 833 (1969). - 234 -65. J.A. Zorge, J . Strating and H. Wynberg, Recueil, 89, 781 (1970). 66. a) J.R. Majer and J.P. Simmons, Advari. Photochem., 137 (1964). b) C. Walling and E.S. Huyser, Org. Reactions, 13, 91 (1963). c) E.W. Steacie, "Atomic and Free Radical Reactions", 2nd ed., Vol. I , p. 397 - 405, 1954. d) P.G. Sammes, "Chemistry of the C-X Bond", Vol. I I p. 747 - 794, 1974. 67. a) R.K. Sharma and N. Kharasch, Arigew. Chem., 80, 691 (1968). b) J . Cornelisse and E. Havinga, Chem. Rev., 75, 353 (1975). 68. J.T. Pinhey and R.D. Rigby, Tetrahedron Lett.. 1271 (1969). 69. L.O. Ruzo, N.J. Bunce and S. Safe, Can. J. Chem., 53, 688 (1975). 70. P.J. Kropp, T.H. Jones and G.S. Poindexter, J.Ame.r. Chem. S o c , 95. 5420 (1973). 71. G.S. Poindexter and P.J. Kropp, J.Amer.Chem. Soc., 96, 7142 (1974). 72. K.S. Bhandari and R.E. Pincock, unpublished r e s u l t s . 73. R.C. Fort and P. von Schleyer, Chem. Rev., 64, 277 (1964). 74. W.B. Scott and R.E. Pincock, unpublished r e s u l t s . 75. P. von Schleyer, R. Fort, W.E. Watts, M.B. Comisarow and G. Olah, J.Amer. Chem. Soc., 86, 4195 (1964). 76. H.D. Hudson, Synthesis, I , 112 (1969). 77. N.L. A l l i n g e r and W. Szkrybalo, J . Org. Chem., 27, 4601 (1962). 78. G. Chirurdoglu and W. Masschelein, B u l l . Soc. Chem. Beiges, 70, 767 (1961). 79. E.L. E l i e l , H. Haubenstock and R.V. Acharya, jjuner. Chem. Soc., 83, 2351 (1961). 80. P. von Schleyer, L.K. Lam, D.J. Raber, J.L. Fry. M.A. McKervey, J.R. A l f o r d , B.D. Cuddy, V.G. Keizer, H.W. Geluk and J.L. Schlatmann, J.Amer.Chem. Soc., 92, 5246 (1970). 81. Z. Majerski, S.H. Liggero, P. von Schleyer, and A.P. Wolf, Chem. Commun., 1596 (1968). - 235 -82. Z. Majerski, P. von Schleyer and A.P. Wolf, J . Amer. Chem. S o c , 92, 5731 (1970). 83. H.F. Reinhardt, J . Org. Chem., 27, 3258 (1962). 84. J . Slutsky, E.M. Engler and P. von Schleyer, Chem.Commun., 685 (1973). 85. E.M. Engler, J.D. Andose and P. von Schleyer, J.Amer. Chem. S o c , 95, 8005, (1973). 86. R.R. Perkins and R.E. Pincock, unpublished r e s u l t s . 87. P.D. B a r t l e t t and E.S. Lewis, J.Amer. Chem. S o c , 72, 1005 (1950). 88. P.D. B a r t l e t t and F.D. Greene, J.Amer. Chem. S o c , 76, 1088 (1954). 89. L. Friedman and F.M. Logullo, J.Amer. Chem. S o c , 85, 1549 (1963). 90. U. Schollkopf, Arigew. Chem., 72. 147 (1960). 91. K. Anzenhofer, J . de Boer, Z. K r i s t a l l b g r . , 131, 103 (1970). 92. K.J. Palmer and D.H. Templeton, Acta. Cryst. B, 24, 1048 (1968). 93. G.A. Olah, G. Liang, P. von Schleyer, E.M. Engler, M.J. Dewar and R.C. Bingham, J.Amer.Chem. S o c , 95, 6829 (1973). 94. G.A. Olah and R.D. Porter, J.Amer.Chem. S o c , 93, 6877 (1971). 95. J.A. Bone and M.C. Whiting, Chem.Commun.,115 (1970). 96. a) J.L. Fry, C.J. Lancelot, L.K. Lam, J.M. Harris , R.C. Bingham, D.J. Raber, R.E. H a l l and P. von Schleyer, J.Amer.Chem. S o c , 92, 2538 (1970). b) J.L. Fry, J.M. Harris , R.C. Bingham and P. von Schleyer, J.Amer.Chem. Soc.. 92., 2540 (1970). c) P. von Schleyer, J.L. Fry, L.K. Lam, and C.J. Lancelot, J.Amer.Chem. '• Soc., 92, 2542 (1970). 97. L.C. Bateman, K.A. Cooper, E.D. Hughes and C.K. Ingold, J . Chem. S o c , 925 (1940). 98. J.M. Harris, D.J. Raber, R.E. H a l l and P. von Schleyer, J.Amer.Chem. S o c , 92, 5729 (1970). - 236 -99. K.H. Yang, K. Kimoto, M. Kawanisl, B u l l . Chem. Soc. Japan, 45, 2217 (1972). 100. H.W. Geluk and J.L. Schlatmann. Tetrahedron. 5369 (1968). 101. K. Kimura and S. Nagakura, Spectro. Acta, 17, 166 (1961). 102. D.N. K e v i l l , K. Kolwyck and F. Weith, J.Amer.Chem. S o c , 92, 7300 (1970) 103. B.W. Mclntyre, M.Sc Thesis, U.B.C., 1976. 104. R.C. Bingham, P. von Schleyer, For t s c h r j t t e der Chemischert Forschung, 18, 74 (1971). 105. N.J. Turro,"Molecular Photochemistry", W.A. Benjamin Inc., 1967. 106. S.P. McGlynn, T. Azumi and M. Kasha, J . Chem.Phys., 40, 507 (1964). 107. S.P. McGlynn, M.J. Reynolds, G.W. Daigne and N.D. Christodouleous, J. Phys. Chem., 66, 2499 (1962). 108. J.G. Calvert and J.N. P i t t s , "Photochemistry", John Wiley and Sons, 1966. 109. F. Cotton, "Inorganic Chemistry", 3rd ed. p. 113, 1972. 110. T. Sasaki, S. Eguchi and T. Toru, B u l l . Chem. Soc. Japan, 41, 236 (1968), 111. V.R. Koch and L.L. M i l l e r , J.Amer.Chem. S o c , 95, 8631 (1973). 112. F. Vincent, R. Tradivel and P. Mison, Tetrahedron L e t t . , 603 (1975). 113. O.M. Soloveichik and V.C. Ivanov, J . Org. Chem. USSR, 2416 (1974). 114. C. Ruchardt, H. Kerwig and S. E i c h l e r , Tetrahedron 'Lett. f 421 (1969). 115. F. Kienzle and E.C. Taylor, J. Org. Chem., 35, 528(1970). 116. Z. Dolejsek, S. Hala, V. Hanus and S. Landa, C o l l . Czech. Chem. Comm., 31, 435 (1966). 117. R.L. Greene, W.A. Kleschick and G.H. Wahl, Tetrahedron L e t t . , 4577 (1971). 118. T.J. Broxton, L.W. Deady, M. Kendall, R.D. Thompson, Applied Spect., 25, 600 (1971). 119. R.C. Fort and T.R. Llndstrom, Tetrahedron, 3227 (1967). 120. H. Spiescke and W.G. Schneider, J. Chem. Phys., 35, 722 (1961). 121. J.R. Cavanaugh and B.P. Dailey, J. Chem Phys., 34, 1099 (1961). - 237 -122 a) R.E. Lack and A.B. Ridley, J. Chem Soc. B. 721 (1968). b) R.E. Lack, J . Nemorin, and A.B. Ridley, J. Chem. Soc. B., 629 (1971). 123. F. van Deursen and P.K. Korver, Tetrahedron L e t t . . 3923 (1967). 124. F. van Deursen and J. Bakker, Tetrahedron. 4593 (1971). 125. a) G.C. Levy, and G.L. Nelson, "Carbon-13 Nuclear Magnetic Resonance for Organic Chemists", Wiley-Interscience, N.Y., 1972. b) J.B. Stothers, "Carbon-13 NMR Spectroscopy", Academic Press, N.Y. 1972. 126. a) T. Pehk, E. Lippmaa, V.V. Sevostjanova, M.M. Krayuschkin and A.I. Tarasova, Org. Mag. Resonance, 3, 783 (1971). b) G.E. Maciel, H.C. Dorn, R.L. Greene, W.A. Kleschick, M.R. Peterson, and G.H. Wahl, Org; ; Mag. Resonance, 178 (1974). 127. H. Spiesecke and W.G. Schneider, J . Chem. Phys., 35, 722 (1961). 128. W.M. Litchman and D.M. Grant, J.Amer.Chem. S o c , 90, 1400 (1968). 129. J . Mason, J. Chem. Soc. A, 1038 (1971). 130. G.L. Anderson and L.M. Stock, J.Amer.Chem. Soc., 91, 6804 (1969). 131. L.H. Meyer and H.S. Gutowsky. J. Phys. Chem., 57, 481 (1953). 132. W. Adcock, M.J. Dewar, R. Golden and M.A. Zeb, J.Amer.Chem Soc.,97, 2198 (1975). 133. G.H. Wahl and M.R. Peterson. J.Amer.Chem. S o c , 92., 7238 (1970). 134. P. von Schleyer, and CW. Woodworth, J.Amer.Chem Soc., 90, 6528 (1970) 135. J . Weber, Dissertation, Tech. Hochschule Aachen, 1966. 136. CW. Woodworth, Ph.D. Thesis, Princeton U., 1968. 137. K. Gerzon. J . Med. Chem., 6, 730 (1963). 138. J . Schmidt, M.Sc. Thesis, U.B.C, Feb. 1972. 139. H. Stetter, Chem. Ber., 102, 3357 (1969). - 238 -140. F. Stepanov. Zh. Org. Khim., 2, 1612 (1966), Chem.Abstr.,66, 64766z. 141. D.C. Nonhebel. Org. Synthesis, 43, 15 (1963). 142. W.; Thielacker and K.H. Beyer, Chem. Ber., 94, 2968 (1961). 143. A.C Yurchenko, Zh. Org. Khim., 1125 (1974), Chem.Abstr.,81, 63225v. 144. CN. Taylor, J . Org. Chem., 37, 2904 (1972). 145. P.M. Subramanian,.M.T. Emerson and N.A.1 LeBel.'J. Org. Chem., 30, 2624 (1965). 146. A.C Davis and R. Tudor. J. Chem. Soc. B, 1815 (1970). 147. S. Winstein and N.J. Holness, J.Amer.Chem. S o c , 72, 5562 (1955). 148. E.L. E l i e l and R.C Haber. J . Org. Chem., 24, 143 (1958). 149. P.S. S k e l l and P.D. Readio. J.Amer.Chem. S o c , 86, 3334 (1964). 150. A. Vogel, " P r a c t i c a l Organic Chemistry", 3rd ed. p. 274. 151. F.D. Greene, C.C. Chu and J. Walia, J. Org. Chem.,29, 1285 (1964). 152. E.J. Corey and J.E. Anderson, J . Org. Chem., 32, 4160 (1967). 153. Handbook of Chemistry and Physics. 154. R. West and P.T. Kevitowski. J.Amer.Chem. S o c , 90, 4677 (1968). 155. S. S z i n a i , Chem.Abstr.,72, P66496j. 156. R.N. Hammer and J . Kleinberg, Inorg. Synthesis, 4_, 12 (1953). 157. A.R. Gagneux and R. Meier. Tetrahedron L e t t . . 1365 (1969). 158. H.C Brown and M.H. Rei. J.Amer.Chem. S o c , 91, 5646 (1969). 159. S. Landa, J . Vais and J. Burkhard, Z. Chem., _7» 2 3 3 (1967). 160. L.J. Feiser, "Experiments i n Organic Chemistry", 3rd ed. p. 167. 161. L.H. Zalkow and A.C. Oehlschlager. J . Org. Chem., 29, 3303 (1963). 162. J . M i l l s and E. Krumkalns. Chem.Abstr..69, P59281v. 163. J.L. Lucha, J . Bertin and H.B. Kagan, Tetrahedron L e t t . , 759, 763 (1974). 164. G.A. Olah, "Friedel-Crafts Chemistry", John-Wiley, N.Y., 1973. 16L5. D. Grant and M.A. McKervey, Chem. Commun. ,,. 297 (1974). - 239 -APPENDIX A) Response Factors (glc) AdH 1.40 AdOH 1.04 AdOMe 1.00 Ad(OMe)0 2.10 1.65 1.60 1.00 B) Deuterium Incorporation Studies 1) 4$"' -non-deuterated mass it Height P (126) 118 mm P + 1 (127) 12 mm P + 1 = 10.2% P deuterated mass # Height P' (126) 44 mm (P'+ 1) (127) 13.5 mm 10.2% P» = 4.5 *, (P' + 1) corrected = 13.5 - 4.5 = 9.0 ' Deuterium incorporation = 9.0 = 17% 9.0 + 44.0 - 240 -2) X = H.D non-deuterated deuterated Mass # Height Mass// Height P (136) 70 mm P'(136) 35 mm P + 1 (137) 10 mm ' (P' + 1^  (137) 6 mm P + 1 = 13.4% P 13.4% P' = 4.8 .". (P' + l)corrected = 1.2 Deuterium incorporation =1.2 = 3.2% 1.2 + 35.0 

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.831.1-0061000/manifest

Comment

Related Items