Open Collections

UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

The pyridine denitration of cis- and trans-1, 2-cyclohexanediol dinitrates. Zane, Alexis 1958-01-12

You don't seem to have a PDF reader installed, try download the pdf

Item Metadata

Download

Media
831-UBC_1958_A6_7 Z2 P9.pdf [ 2.87MB ]
Metadata
JSON: 831-1.0062227.json
JSON-LD: 831-1.0062227-ld.json
RDF/XML (Pretty): 831-1.0062227-rdf.xml
RDF/JSON: 831-1.0062227-rdf.json
Turtle: 831-1.0062227-turtle.txt
N-Triples: 831-1.0062227-rdf-ntriples.txt
Original Record: 831-1.0062227-source.json
Full Text
831-1.0062227-fulltext.txt
Citation
831-1.0062227.ris

Full Text

THE PYRIDINE DENITRATION OF CIS- AND TRANS-1,2-CYCLOHEXANEDIOL DINITRATES By ALEXIS ZANE A Thesis submitted i n P a r t i a l Fulfilment of Requirements for the Degree of Master of Science i n the Department of Chemistry We accept t h i s thesis as conforming to the standard requirements from candidates for the degree of Master of Science Members of the Department of Chemistry The University of B r i t i s h Columbia May, 1 9 5 8 . ABSTRACT Refluxing c i s - and trans- 1 . 2-cyc 1ohexanedio 1 d i n i t r a t e s i n excess anhydrous pyridine at l l 8 ° - 1 2 0 ° C lead to a slow decomposition of the d i n i t r a t e s and the < formation of a gaseous product. It was found that the tra n s - d i n i t r a t e decomposed 1 . $ times f a s t e r than the cis-isomer, and that no 2-nitroxyCyclohexanols or 1 , 2 - cyclohexanediols were formed. Nine components were detected i n the reaction mixture by paper chromatography. Pyridinium n i t r a t e , succinic and adipic acids, and a polymer were shown to be- produced i n the trans-denitration mixture. The use of 3-methylheptane i n place of pyridine as solvent gave the decomposition products: oxalic, succinic and adipic acids, water, carbonized material, a reddish- brown gas and unsaturated compounds. The reaction of quinoline with the tr a n s - d i n i t r a t e at l6.f?,0C yielded mainly water and a pyridine soluble polymer. In presenting t h i s thesis i n p a r t i a l fulfilment of the requirements for an advanced degree at the University of B r i t i s h Columbia, I agree that the Library s h a l l make i t f r e e l y available for reference and study. I further agree that permission for extensive copying of t h i s thesis for scholarly purposes may be granted by the Head of my Department or by his representative. It i s understood that copying or publication of t h i s thesis f o r f i n a n c i a l gain s h a l l not be allowed without my written permission. Department of The University of B r i t i s h Columbia", Vancouver 8 , Canada. Date ACKNOWLEDGEMENTS The writer wishes to express his sincere thanks to Dr. L. D. Hayward f o r his encouragement and w i l l i n g assistance i n the di r e c t i o n of this i n v e s t i g a t i o n . The f r i e n d l y advice of Mr. M. Jacks i s likewise g r a t e f u l l y acknowledged. May, 1 9 ^ 8 Alexis Zane TABLE OF CONTENTS Page GENERAL INTRODUCTION 1 HISTORICAL INTRODUCTION . 2 DISCUSSION OF RESULTS 2 1 A. e l s - and trans- Cyclohexanediol D l n l t r a t e s . . 2 1 B. e l s - and trans- 2-Nitroxycyclohexanols 2 1 C. Decomposition of c i s - and trans- 1 , 2 - Cyclo hexanediol Dinitrates 2 3 CONCLUSIONS 3 1 EXPERIMENTAL 3 3 A. Materials 3 3 B. Syntheses of 1,2- Cyclohexanediol D i n i t r a t e s . 3 6 C. Syntheses of 2-Nitroxycyclohexanols 3 6 D. Decomposition of c i s - and trans- 1,2- Cyclohexanediol D i n i t r a t e s i n Pyridine Solution 40 (a) Preliminary Experiments 40 (b) I s o l a t i o n of the Unreacted D i n i t r a t e . . . 41 (c) Fractionation of the Aqueous-Pyridine Residue 42 (d) I s o l a t i o n of the Mononitrate 45 (e) Examination of the D i s t i l l a t e from the Reaction Mixture 46 E. Decomposition of trans- 1,2-Cyclohexanediol D i n i t r a t e i n 3-Methylheptane Solution 49 (a) Preliminary Experiments . . . . 49 (b) I s o l a t i o n of the Unreacted D i n i t r a t e . . . 5 0 (c) Examination of the D i s t i l l a t e from the Reaction Mixture 5 2 F. Decomposition of trans- 1,2-Cyclohexanediol D i n i t r a t e i n Quinoline Solution 5 3 BIBLIOGRAPHY 1 GENERAL INTRODUCTION In recent years Hay-ward and coworkers have shown that the action of dry pyridine on the hexanitrates of manni.tol and d u l c i t o l s e l e c t i v e l y removed the 3- (or chem i c a l l y equivalent 4-) nitrate:; group. A similar p a r t i a l d e n i t r a t i o n of the p e n t i t o l pentanitrates was also observed. The r e l a t i v e rates of these reactions appeared to be a function of the configuration of the a c y l i c molecules. In an attempt to determine the required stereo chemical rel a t i o n s h i p between n i t r a t e ' groups for s e l e c t i v e denitration, c i s - and trans- 1,2-cyclohexanediol d i n i t r a t e s of known configuration were selected for study. As these isomers may have d i f f e r e n t conformations, i t was expected that they would show some s e l e c t i v i t y and difference i n r e a c t i v i t y toward pyridine. 2 HISTORICAL INTRODUCTION A. Selective Denitration of Polynitrate Esters Wigner i n 1 9 0 3 ( 7 1 ) observed that a l c o h o l i c pyridine reacted with mannitol hexanitrate to give a pentanitrate, but that the reagent had no e f f e c t on d u l c i t o l hexanitrate even at the b o i l i n g point. On the other hand, he found that warm, dry pyridine caused a reaction accompanied by evolution of a gas and the formation of d u l c i t o l pentanitrate. This work was con firmed by McKeown and Hayward i n 1 9 5 5 (4-4) who showed that the denitrating action of the pyridine i s s p e c i f i c to the 3 - (or equivalent 4-) p o s i t i o n of the d u l c i t o l hexanitrate. Hayward ( 3 D had e a r l i e r shown that D- mannitol - 1 , 2 , 3 , 5 * 6 - pentanitrate was obtained by pyridine reaction on D- mannitol hexanitrate at room temperature. No inversion of configuration occured i n these sel e c t i v e reactions. The gas produced from the D- mannitol hexanitrate was analyzed by Brown and Hayward (14). From a O . 3 6 8 M solution of the hexanitrate i n pyridine at 3 0 + 5°C> a gas consisting of n i t r i c oxide, nitrous oxide, and nitrogen was evolved. The amount and composition of the gas mixture were sensitive to traces of moisture i n the pyridine. Establishment of a material balance for the reaction indicated that approximately two moles of pyridine suffered r i n g cleavage while 0 . 2 5 moles of hexa n i t r a t e was completely denitrated and 0 . 7 5 moles of pentanitrate was found. E l r i c k and collaborators ( 2 3 ) have recently shown that 3 treatment of D-mannitol hexanitrate with an aqueous acetone solution of ammonium carbonate also gave a good y i e l d of the same D-mannitol pentanitrate. Tichanowitsch (59) i n 1864 had obtained a pentanitrate of mannitol by passing dry ammonia gas into an etheral s o l u t i o n of mannitol hexanitrate. Bowering i n 1956 (12) found that the newly synthesized a l l i t o l hexanitrate reacted more slowly with dry pyridine at room temperature than the corresponding D-mannitol d e r i v a t i v e , and produced pyridinium n i t r a t e but no gaseous products. A 76% y i e l d of an o i l y product which was thought to be the pentanitrate was obtained. Wright (70) i n 1957 synthesized and i d e n t i f i e d the new explosive compounds x y l i t o l , y i b i t o l and L - a r a b i t o l penta- n i t r a t e s . These c r y s t a l l i n e compounds reacted with dry pyridine i n much the same manner as the h e x i t o l hexanitrates. The x y l i t o l d erivative evolved more gas and gave a reaction mixture darker i n color than those obtained with the a r a b i t o l and F i b i t o l com pounds. P a r t i a l l y denitrated syrups were recovered from each of the three pyridine solutions on d i l u t i o n with water. Jackson (35) i n 1957 prepared the d i n i t r a t e s of the three known 1,4 : 3»6- dianhydrohexitols (isomannide, i s o - sorbide and isoic^dide) and tested t h e i r reaction with pyridine. Isomannide d i n i t r a t e was found to react more r a p i d l y than i s o - sorbide d i n i t r a t e , and the l a t t e r faster than isolodide d i n i t r a t e . The inves t i g a t i o n of the reaction products i s s t i l l going on. The action of pyridine on n i t r o c e l l u l o s e has also been 4 studied. Angelis(2) found that pyridine-moistened n i t r o  c e l l u l o s e gave an 80$ y i e l d of the o r i g i n a l weight of n i t r o  c e l l u l o s e with a nitrogen content reduced from an o r i g i n a l 12$ to 9-10$ nitrogen indicating decomposition. Giannini ( 2 6 ) extended t h i s work i n 1924, and showed that a gas containing carbon dioxide, n i t r i c oxide, nitrous oxide, and nitrogen was given o f f . In 1944 Gladding and Purves (28) found that pure, dry pyridine caused a vigorous decomposition of dissolved, s t a b i l  ized gun-cotton at 100°C. Pyridine-induced elimination reactions were shown to occur by Lame ( 3 9 ) i n 1953* Secondary and t e r t i a r y n i t r a t e s refluxed with pyridine formed o l e f i n s . Thus cyclohexyl n i t r a t e and t e r t i a r y butyl n i t r a t e gave cyclohexene and butylene respectively. Primary n i t r a t e esters formed quaternary ammonium sa l t s (26,39) Ryan and Casey (54) i n 1928 studied the effect of primary, secondary and t e r t i a r y amines on various carbohydrate n i t r a t e esters. Dimethylaniline reacted with mannitol hexanitrate at an elevated temperature to evolve a gas consisting of 70% nitrous oxide and 3 0 $ nitrogen. T e r t i a r y a l i p h a t i c amines reacted at r e f l u x temperatures with primary n i t r a t e esters to form quarternary s a l t s (26,39) In 1946 Segall (55) showed that excess hydroxylamine i n pyridine at room temperature acted on c e l l u l o s e t r i n i t r a t e to give a c e l l u l o s e d i n i t r a t e with the evolution of one mole of nitrogen per mole of an-hydroglucose. The n i t r a t e groups 5 attacked proved to be secondary i n nature. The product was stable to pyridine. Methorylamine reacted s i m i l a r l y except that no nitrogen was evolved. With excess hydroxylamine hydro chloride the product appeared to be a c e l l u l o s e ketoxime d i n i t r a t e and the gas evolved consisted of 8 5 $ nitrous oxide and 15% nitrogen. Falconer and Purves ( 2 5 ) recently showed that the hydroxylamine-pyridine s o l u t i o n at room temperature reacted with c e l l u l o s e t r i n i t r a t e to give c e l l u l o s e - 3 , 6 - d i n i t r a t e , a baoo stable compound. Hayward ( 3 2 ) investigated the action of free hydro- xylamine i n pyridine on methyl-ifr- and p-D-glucopyranoside t e t r a n i t r a t e s . He found that an alcoholic solution of hydro- xylamine had l i t t l e or no eff e c t on these compounds, but that a vigorous exothermic reaction ensued on addition of hydroxy- lamine i n anhydrous pyridine to methyl -p-D-glucoside t e t r a - n i t r a t e . Nitrogen gas was evolved i n the r a t i o of 1 . 3 moles per mole of t e t r a n i t r a t e , and the product contained methyl-p-D- g l u c o s i d e - 2 , 3 , 6 - t r i n i t r a t e ( 5 3 $ )» methyl -B-D-glucoside - 3 , 6 - d i n i t r a t e (33%)» and an unidentified methyl -B-D-glucoside t r i  n i t r a t e . Rooney ( 5 3 ) showed that methyl -p-D-glucopyranoside t e t r a n i t r a t e reacted slowly with hydroxylamine hydrochloride i n pyridine at room temperature and evolved a gas composed of 70% nitrous oxide and 30% nitrogen. The syrupy products obtained consisted of a mixture of p a r t i a l l y n i t r a t e d methyl-glucosides and completely denitrated polyoxime products. 6 Methyl - p-D-glucopyranoside - 2 , 3 , 6-trinitrate and a substance believed to be methyl-jB-D-glucopyranoside - 2 , 6-dinitrate were is o l a t e d . When simple a l k y l n i t r a t e esters were heated with ammonia, or primary or secondary a l i p h a t i c amines, N-alkylation occurred. Piperidine ( 2 7 ) and diethylamine have been alkylated by heating with primary, secondary, and t e r t i a r y a l k y l n i t r a t e s . The action of quinoline on methyl-£-D-glucoside t e t r a n i t r a t e was also investigated by Swan ( 5 8 ) . Some de- n i t r a t i o n occurred accompanied by evolution of a gas. B. Mechanism of Denitration Recent studies ( 5 , 6,41) have established the simul taneous occurrence of three d i s t i n c t reactions i n the al k a l i n e cleavage of n i t r a t e esters. These reactions, i l l u s t r a t e d with hydroxide ion, are as follows: (§) Nacleophilic s u b s t i t u t i o n HO" + R 0 W 0 2 tr+> ROH + NO^" (b) Elimination of p-hydrogen H 0 ~ + R-CH 2CH 2 0N0 2 — * RCH - CH2 •* H 2 0 + N O 3 " (c) Elimination of <?c - hydrogen HO" + RCH 2 0 N 0 2 — » RCH « 0 + H 2 0 + N 0 2 ~ Neutral hydrolysis occurs too, where water acts as a nucleo- p h i l i c agent. 7 HO + -C- X — ^ HO-C- + X where X = 0W02 or a halogen. However, i n a l k a l i n e hydrolysis there i s some retention of con f i g u r a t i o n i n going from n i t r a t e to alcohol. The most reasonable mechanism appears to be that involving cleavage of the 0-N bond, analogous to the usual acyl-oxygen cleavage i n carboxylate esters (22). A base independent carbonium ion process (SN1) i s also available. This was shown to take place i n alcohol-producing hydrolyses of t e r t i a r y butyl n i t r a t e and p a r t i a l l y i n the neutral hydrolysis of isopropyl n i t r a t e ( 5 ) » Olefin-formation occurs must extensively i n the hydrolysis (either neutral or alkaline) of t e r t i a r y butyl n i t r a t e ( 5)41) but small amounts of o l e f i n are found i n the alkaline hydrolyses of ethyl (2$) and isopropyl (10$) n i t r a t e s ( 5 ) . It has been d e f i n i t e l y established that N02~ i s formed d i r e c t l y from the n i t r a t e ester, and i s not the r e s u l t of a secondary reaction i n which alcohol i s oxidized to aldehyde ( 5 ) . It appears that pyridine, and mixtures of pyridine and hydroxylamine, and other;amines, cause nitroxy-bond cleavage of n i t r a t e esters. Segall i n 1946 ( 5 5 ) postulated the following reaction on the basis of the l a b i l e hydrogen atom i n hydroxy lamine: 8 Hayward and coworkers ( 3 1 , 3 2,44) and Rooney ( 5 3 ) showed that no inversions occurred i n the den i t r a t i o n reactions with pyridine, and pyridine and hydroxylamine mixtures. In the thermal decomposition of n i t r a t e esters, most investigators agree that the i n i t i a l step i s the s c i s s i o n of the nitroxy bond to give N0 2 and an alkoxyl r a d i c a l (R0«) ( 3 , 5 0 , 4 0 , 6 8 ) . Thermal decomposition of c e l l u l o s e n i t r a t e produced carbon monoxide, carbon dioxide, n i t r i c oxide, nitrous oxide, nitrogen dioxide, nitrogen, methane, hydrogen, water and formalde hyde ( 6 8 ) . Working at 3 0 mm pressure Wolfrom ( 6 8 ) reported water, formic acid, formaldehyde, glyoxal and carbonyl compounds as the main thermal decomposition products. He suggested that the i n i t i a l product at any pressure was a fragmented oxycellulose n i t r a t e . The l i g h t e r the ambient pressure, the greater was the proportion of t h i s i n i t i a l product undergoing additional degrada t i o n . As the pressure increased above 6 0 mm., a l l the fragmented oxycellulose n i t r a t e disappeared and the rate of change i n the y i e l d s of the organic products with pressure decreased, producing a range of pressure ( 2 0 0 - 5 0 0 mm.) i n which the y i e l d s were almost pressure independent. The value for the t o t a l carbonyl, however, decreased s t e a d i l y with pressure which could, he explained, bp due to the further oxidation of formaldehyde, glyoxal and formic acid, and that the three l a t t e r compounds were produced by the further degradation of the more complex e n t i t i e s ( t r i o s e s , e t c . ) . The possible mechanisms are shown below: CHzONC-i Q C H t O W O ^ 0 o w c c O N O ^ O H C - C - O R H t H H 1 P> - o . /C = 0 c ' v c = o B E H-C =0 1 0 With v i c i n a l d i n i t r a t e s , Kuhn and Angelie ( 3 8 ) showed that c i s - and t r a n s - 1 , 2 - cyclohexanediol d i n i t r a t e s i n vapour form were degraded at 2 6 0 ° - 280°C to higher than 70% y i e l d s of adipaldehyde and n i t r i c oxide. They proposed the following mechanism: RCH(0N0)-CH(ONO)R — * RCH(0*)-CH(0N0)R • NO 2 RCHO + NO. In the l i q u i d state and i n a nitrogen atmosphere, 70% of the decomposed t r a n s - l , 2 - d i n i t r i t e s could be i d e n t i f i e d as aldehyde, dialdehyde, d i o l and oc-hydroxy-ketone. C. Conformational Studies of 1 , 2-Cyclohexane Derivatives It i s well known that a r e l a t i o n s h i p exists between the conformation of cyclohexane derivatives and t h e i r physical pro p e r t i e s . ( /^>^«-rs-Skita Rule). P i t z e r and Beckett (49) and l a t e r workers ( 1 , 8 ) have shown that for c i s - trans-pairs of disub- st i t u t e d cyclohexanes, the isomer which has the higher index of r e f r a c t i o n and the higher density i s the isomer with the lowest conformational s t a b i l i t y . It was shown by Ottar i n 1947 that both a x i a l and equatorial oxygen atoms exist i n both the c i s - and trans-cyclo- hexane-l , 2-diols. The d i a x i a l conformation i s understood to pre dominate i n the case of the t r a n s - d i o l ( P i t z e r , Review 1 9 5 6 ) . In 1 9 5 0 , Smith and Byrne ( 5 6 ) showed that the r e l a t i v e 11 rates of e s t e r i f i c a t i o n of cyclohexane-1,2- tricarboxylic acids depend on the geometrical and p o s i t i o n a l arrangement of the carboxyl groups, p a r t i c u l a r l y on the number of equatorial groups available for reaction. From the rate constants obtained for acid-catalyzed e s t e r i f i c a t i o n , the c i s - isomer was found to be e s t e r i f l e d twice as fast as the trans- isomer. It was concluded that the trans- isomer had an a x i a l - a x i a l conformation, whereas the c i s - a c i d was a x i a l - e q u a t o r i a l . K i l p a t r i c k and Morse ( 3 6 ) i n 1953 showed that the d i s s o c i a t i o n constant of an acid depended upon the structure of the molecule and was a function of the o r i e n t a t i o n and s p a t i a l i n t e r a c t i o n of dipolar groups and the distance of the dipolar centers from the ionizable proton. The trans-1,2- cyclohexane- dicarboxylic acid and the trans- -1- hydroxy-cyclohexane -2- carboxylic acid were stronger i n water than the corresponding c l s - isomers, but weaker i n solvents of lower d i ^ e l e c t r i c constants (methanol, ethanol, and ethylene g l y c o l ) . It was concluded that the more stable configuration was the one i n which the distance between the groups was largest, thus favoring the a x i a l - a x i a l conformation over the equatorial-equatorial f o r the trans- isomer. Hence, the trans- isomer was d i e q u a t o r i a l i n water, but d i a x i a l i n non-aqueous solvents. Pascual (48) i n 1949 showed that the d i f f e r i n g r e a c t i v i t y of the hydroxyl and carboxyl groups i n 1- hydroxyeyelohexane -2- carboxylic acid must be r e l a t e d to the conformation. The trans- isomers were found to be less reactive than the c i s - isomers. These differences were ascribed to the r e l a t i v e l y greater ease of 12 e s t e r i f l c a t i o n and hydrolysis of an equatorial as compared with an a x i a l substituent. The trans-isomers of 1,2- dihalocyclohexane were shown to exist as equilibrium mixtures of the d i a x i a l and the diequa- t o r i a l conformations (10). T u l i n s k i e and collaborators ( 6 2 ) found that the dipole moment of trans-1,2- dichloracyclohexane at 40°C i n benzene solut i o n almost equalled that i n vapour state at 2 3 9°C, showing an absence of any appreciable s h i f t to another form of di f f e r e n t moment with change of temperature and molecular environ ment. The trans- 1,2- dichlor^cyclohexane was estimated to have 5 6 $ equatorial-equatorial form i n the gaseous state ( 2 3 9°C) and 7 2 $ i n benzene at 40 GC. D. Elimination Reactions of 1,2- Cvclohexane' Derivatives The elimination of t o s y l (p- tolvenesulfonyl) groups from the cyclohexane ring has been studied i n some d e t a i l . The most common reactions of esters o f . s u l f o n i c acids are nucleophilic displacements, by the SN1 and SN2 mechanisms, at the a l k y l carbon atom. Nucleophilic attack on sulfur i s not observed unless the r e a c t i v i t y at the a l k y l carbon atom i s markedly decreased. Bunton and F r e i (16) i n 1951 showed that the 1 8 a l k a l i n e hydrolysis of phenyl-p-tolwenesulfonate i n H 20 1 8 solution introduced the 0 atom into the p- tolwene sulfonate but not the phenolate. C 7H y-S0 2-OC 6H 5 + H 2 0 1 8 — * C ?H 7S0 20 l 8H + C ^ O " 1 3 Detosylation i n carbohydrates with sodium iodide i n cdcetone solution was found by Oldham and Rutherford i n 1932 (47) to be r e s t r i c t e d to the primary tosylate groups. Some exceptions (11,61,46) to t h i s generalization have been reported, and i t now appears that a secondary tosylate group may be reactive towards sodium iodide i f i t i s contiguous to one i n a primary p o s i t i o n . There are also a few cases (34) of an i s o l a t e d secondary tosylate reacting with sodium iedide. Quite recently Tipson, Clapp and Cretcher (60) have shown that the tosylate group of some secondary a l i p h a t i c alcohols, and of cyclohexanol, borneol, and menthol, reacted with sodium iodide to form sodium to s y l a t e . Evidently the secondary tosylate groups i n these compounds are considerably more reactive than are similar groups i n a carbohydrate molecule. The other products of the reaction were not i d e n t i f i e d . Clark and Owen (17) i n 1949 found that the trans -2- hydroxycyelohexyl-p-tolvene sulfonate reacted r e a d i l y with sodium iodide i n cicetone solution at 85°C to give a f t e r f i v e hours a high y i e l d of sodium tosylate and trans-2-iedocyclohexanol. Winstein and Buckles (64 , 6 5 ) i n 1942 showed that trans-1- bromo-2-acetoxycyclohexane and trans -1,2- dibromocyclohexane with s i l v e r acetate i n dry g l a c i a l acetic acid produced trans- diacetates, whereas with the presence of small amounts of water inversion took place. They also observed that cis-2-chlorocyclo- hexylacetate was unaffected by s i l v e r acetate under conditions i n which the trans-isomer r e a d i l y gave trans-diacetate. These workers attributed the low r e a c t i v i t y of the c i s - derivatives to i t s i n  a b i l i t y to form an intermediate ring- compound. 14 In 1948, Winstein and coworkers ( 6 7 ) studied the rates of acetolysis of tosyl-oxycyclohexane, I, trans - 2-acetoxytosyloxy- cyclohexane, I I , and cis - 2-acetoxytosyloxycyclohexane, I I I , i n g l a c i a l acetic acid. They showed that the r e l a t i v e r e a c t i v i t i e s were: I, l*OCy>II, O 3 0 ^ > I I I , 4.5 x 1CT 4. Also, the t r a n s - 2 - acetoxy-p-bromo-benzenesulfonoxycyclohexane was found to be 6 3 O times more reactive than the corresponding cis-isomer. Both acetolyses yielded the trans- diacetate. In order to correlate the observed r e a c t i v i t i e s , Winstein and coworkers suggested that the reaction of the trans - 2-acetoxycyclohexyltosylate, I, pro ceeded by way of a one-stage r i n g closure mechanism to y i e l d the acetoxonlum ion, I I , and that t h i s process involved a much more favourable free-energy of a c t i v a t i o n than does the formation of the ion, I I I , by d i s s o c i a t i o n of the c i s - ester, IV, f o r which p a r t i c i p a t i o n of the neighbouring acetoxy group would involve p r o h i b i t i v e s t r a i n . Furthermore, the p a r t i c i p a t i o n of neighbouring groups i n the replacement reactions were calculated to be i n the order of decreasing a c t i v i t y as follows: l)>0Ac./> Br y OCH3. Neigh bouring chlorine atom or hydroxy group showed l i t t l e tendency for p a r t i c i p a t i o n and i n these cases the rate - determining ion i z a t i o n was predominantly the formation of the open carbonium ion. where AS = I, OAc, Br, O C H 3 , CI, OH. In c i s - and trans- 1,2- dibromobenzenesulfonoxycyclohexane, the rate constants for acetolysis was found to be equal. Therefore, Winstein concluded, the arenesulfonoxy groups were i n a f f e c t i v e i n t h i s p a r t i c i p a t i o n . Clarke and Owen (17) i n 1949 supported the views of Winstein and coworkers ( 6 7 ) i n intermediate r i n g formation i n 1 6 t h e i r observations of the much greater r e a c t i v i t y of the t r a n s - 2 - hydroxycyclohexyl-p-tolvene sulfonate and trans - 2-hydroxycyclohexyl- methane sulfonate toward a l k a l i , sodium iodide and lithium chloride as compared to the c i s - derivatives. The trans- compounds with a l k a l i , sodium iedide or lithiu m chloride gave cyclohexene oxide, trans - 2-l6docyclohexanol or trans-2-chlorocyclohexanol respec t i v e l y . The c i s - compounds, with a l k a l i , gave cyclohexanone, and with the aqueous reagent, cis-cyclohexane - 1 , 2 - d i o l , and reacted only slowly with sodium iodide or lithium chloride.. Replacement of the sulfonyloxy group i n the trans- series resulted i n o v e r a l l retention of configuration, probably as a r e s u l t of two successive inversions, whilst i n the c i s - s e r i e s , where formation of an intermediate c y c l i c compound was less l i k e l y , a single inversion occurred. C r i s t o l and Fran*us ( 1 9 ) i n 1 9 5 7 studied the rate con stants for acetolysis of c i s - and trans - 2-nitroxy-p-tolvene- sulfonoxycyclohexane, and c i s - and trans - 2-nitroxybromobenzene- sulfonoxycyclohexane i n acetic acid at 8 8°C. They found that the trans-isomers were less than twice as reactive as the corres ponding cis-isomers, and very much less than the corresponding acetoxy compounds studied e a r l i e r by Winstein ( 6 7 ) . The a f f e c t of the nitroxy groups seemed to be limited to t h e i r inductive effect (similar to the cis-acetoxy and the avenesulfonoxy groups of Winstein ( 6 7 ) ) which thus slowed down the rate s i g n i f i c a n t l y . An intermediate, such as the one shown below may have been f<narai;ed • 1 7 II o The elimination process may be s t e r e o s p e c i f i c , but, i n c e r t a i n cases at l e a s t , i s not the rate determining step of the o v e r a l l reaction. C r i s t o l and coworkers ( 2 0 ) i n 1 9 5 6 found that the elimination with sodium iodide i n n-propyl alcohol at 70°C of trans - 1 , 2-dibromocyclohexane, trans - 2-bromocyclohexyl-p- tolvene sulfonate, and trans-2-bromocyclohexyl-p-bromobensene- sulfonate followed the r e a c t i v i t y r a t i o s of 1 : 2 3 : 9 0 respectively. This appeared to be consistent with the concerted elimination process of equation I, where the carbon-X bond i s broken. -C-C- > -C = C - > IBr + X" + - c = c - Br 1 ! Br I where X : OTs, Br, OBs. A reasonable path for the o v e r a l l slow c i s - elimination was postulated as follows: X _C-,:C- + I ^ -C- C- + OTs" I i ' • Br OTs Br 18 C i s - and trans-2-bromocyclohexyl n i t r a t e s were found to have the same rates of elimination and were also much slower as compared to the c i s - atrenesulfonate derivatives. Assuming that the r a t e - determining step i n either case involved displacement of either bromide or n i t r a t e (more l i k e l y bromide) by iodide, then, accord ing to C r i s t o l and coworkers, the following mechanism was possible. 0 N 0 2 Br 6N0 2 s l o w ' I l l -L I 1 -C-C- ^ -C -C- + Br" (trans-iodo) I" rapid ONOo 1 1 c - I 2 + -C = C - + Br I"J fast and -C-C- i > -c -C- Br' s l o w I 0N0 2 (cis-iodo) The cis-iodo compound r e s u l t i n g from displacement on the trans- isomer might be expected to epimerise with iodide ion i n a r e l a t i v e l y f a s t process and thus render unimportant the question of whether a c i s - or a trans- iodo compound was formed. The lower rate constants of the n i t r a t e esters were thought to be due to the r e l a t i v e ineffectiveness of n i t r a t e as a displaceable group compared with bromide or arenesulfonates ( i n trans-19 elimination), or that of bromide or n i t r a t e compared with arene- sulfonate ( i n the f i r s t step of the process with the c i s - isomers). The concept of displacement preceding c e r t a i n eliminations i n these c y c l i c systems finds considerable support i n recent work of Hine and Brader ( 3 3 ) . a cyclopentane r i n g was studied by Barton ( 7 ) i n 1 9 5 0 . A 1 , 2 - s h i f t occurs i n which the r i n g bond plays the part of the migrating group. Only an equatorial substituent can form part of the trans- system necessary f o r such a 1 , 2 - s h i f t to occur. studied by Pollack and Curtin ( 5 D and McCasland ( 4 3 ) . The possible conformations of the c i s - and trans- compounds are shown i n (I) and ( I I ) . Ring contraction where a cyclohexane ri n g contracts to The rearrangements of 2-amino-cyclohexands nave been C I S - Q. T R M M S - O H McCasland (43) i n 1951 found that the trans-2-amino- cyclohexanol on treatment with nitrous acid gave a high y i e l d of cyclopentylmethanol, which indicated that (II) reacted as (IIA) (equatorial-equatorial), and not as (IIB) ( a x i a l - a x i a l ) The cis-2-aminocyclohexanol ( I ) , however, yielded a mixture of the cyclo-entylmethanol and cyclohexanone i n d i c a t i n g that i t reacted p a r t l y as (IA) and p a r t l y as (IB). An a x i a l - a x i a l con formation would give an epoxide. This work and the work of Barton i n 1950, explained the formation of an epoxide and a Ketone i n Clarke and Owen's (17) work of 1949. Although, most of the t r a n s - l , 2 - d i - s u b s t i t u t e d cyclohexane compounds i l l u s t r a t e d here were found to be much more reactive than the corresponding cis-isomers, a few exceptions did occur. The rates of acetolysis of c i s - and t r a n s - 2 - n i t r oxybr omo.b enz ene s.u If onoxyc y c 1 ohe.xan e were very much less than the corresponding acetoxy compounds, and i t seemed that the inductive effect of the nitroxy groups were respon s i b l e . The rates of elimination with sodium iodide of c i s - and trans - 2-bromocyclohexylnitrates were found to be the same, and were also much slower as compared to the cLs.-arenesulfon- a.te. derivatives. The n i t r a t e seemed to be i n e f f e c t i v e here as a displaceab.le group. 21 DISCUSSION OF RESULTS  A« c i s - and trans- Cyclohexanediol D i n i t r a t e s These compounds were prepared so that t h e i r behavior with pyridine could be investigated and compared with the r e s u l t s of previous investigations of the pyridine-denitration reactions. ( 3 1 , 3 9 , 4 4 ) trans-l , 2-Cyclohexanediol d i n i t r a t e was f i r s t syn thesized i n 1951 by C h r i s t i a n and Purves (18) by the n i t r a t i o n of the trans-l T 2-cyclohexanediol. Their compound had m.p . l 8 . 5 ° - o 19 C. Soffer and coworkers ( 5 7 ) and Brook and Wright ( 13) reported b.p . 9 2 ° - 93°C at 1 mm. and n^ 7 1 * 4 7 3 2 , and b.p. 118°C 20 at 5«5 mm. and nip 1*4756 respectively. The trans- d i n i t r a t e prepared for t h i s work was a colorless o i l with b.p.66° - 67°C at 0 . 0 3 mm. and n D 2 7 * ^ 1*4732. c i s - 1 , 2 - Cyclohexanediol d i n i t r a t e was also o r i g i n a l l y made by C h r i s t i a n and Porves ( 1 8 ) by the n i t r a t i o n of the c l s - 1 , 2-cyclohexanediol i n a n i t r i c - s u l f u r i c acid mixture at o°C (m.p. 24 . 5 ° - 2 5°C). Soffer and coworkers ( 5 7 ) , using a n i t r i c - acetic acid-acetic anhydride mixture, obtained an o i l a f t e r vacuum d i s t i l l a t i o n of the crude product, b.p. 1 0 6 ° - 108°C at 1 mm. and i ^ 2 ? 1*4758. The c i s - d i n i t r a t e was prepared for t h i s work according to Soffer's method and had b.p. 1 0 6 ° - 108°C at 1 mm. and . 1 » 4 7 5 7 . B. c i s - and trans- 2-Nitroxycyclohexanols Since c i s - and trans- 2-nitroxycyclohexanols were l i k e l y 2 2 products i n the pyridine reaction on the corresponding d i n i t r a t e s , samples of these compounds were synthesized by established methods. trans- 2-Nitroxycyclohexanol was f i r s t prepared by Brook and Wright ( 1 3 ) i n 1 9 5 1 by a 1 0 0 $ n i t r i c acid n i t r a t i o n of 1 , 2 - epoxycyclohexane. Their product was obtained as a colorless o i l ( 5 5 $ y i e l d ) with b.p. 1 0 0 ° - 105°C at 3 . 5 mm. and n D 2 0 1 » 4 7 8 9 . The trans- 2-nitroxycyclohexanol prepared for t h i s work was made by treating trans- 2-bromocyclohexanol ( 6 4 ) with s i l v e r n i t r a t e i n dry a c e t o n i t r i l e at 0°C. After d i s t i l l a t i o n (b.p. ? 8°C at 0 . 7 5 mm.), the o i l r e a d i l y c r y s t a l l i z e d out i n the cold to a colorless s o l i d (m.p. 2 9 ° - 3 1°C) c i s - 2-Nitroxycyclohexanol was prepared for t h i s work before the synthesis of C r i s t o l and Franzus ( 1 9 ) appeared i n the journals i n 1 9 5 7 * c i s - 1 , 2 - Cyclohexanediol was p a r t i a l l y acetylated by the method of Winstein ( 6 5 ) to give a co l o r l e s s o i l y product aft e r vacuum d i s t i l l a t i o n , (b.p. 103°C at 4 . 5 mm. 24 *J and n D *J 1 * 4 5 7 2 ) . This o i l i s believed to be a mixture of the monoacetate and the diacetate ( 1 9 , 6 5 ) . N i t r a t i o n of t h i s product at - 1 0°C i n a n i t r i c acid-phosphorus pentoxide mixture yielded a c o l o r l e s s o i l (b.p. 93°C at 1 » 3 mm. and n D 2 4 ' ^ 1 * 4 5 3 7 ) . C r i s t o l and Franaus ( 1 9 ) , using a n i t r i c - s u l f u r i c acid mixture at - 7 0°C obtained a colorless o i l after d i s t i l l a t i o n with b.p. 6 8 ° - 7 3°C at 0 » 5 mm. These products probably contained some diacetate. Deacetylation of the c i s - l-acetoxy - 2-nitroxycyclo- hexane was ca r r i e d out i n d i l u t e barium methylate-methanol solution. C r i s t o l and Franeus ( 1 9 ) using a l * 4 M-sodium hydroxide 2 3 s o l u t i o n i n 7 5 $ ethanol, and obtained a 5 4 $ y i e l d of a c o l o r l e s s o i l with b.p. 63°C at 0 . 3 mm. and n D 2 0 1 « 4 7 9 7 . The barium methylate-methanol method gave a 3 6 $ y i e l d of the mononitrate. C. Decomposition of c i s - and trans- 1 , 2 - Cyclohexanediol D i n i t r a t e s . Refluxing the respective d i n i t r a t e s i n excess dry pyridine at 116° - 120°C caused a decrease i n d i n i t r a t e content with time. (Figure 1 . ) . The decomposition of the d i n i t r a t e s was a " F i r s t Order Reaction" i n that the plot of the logarithm of the concentration of unreacted d i n i t r a t e against reaction time gave a straight l i n e for both the c i s - and the trans- isomers. The trans- d i n i t r a t e decomposed 1.8 times faster than the c i s - d i n i t r a t e as shown by the calculated h a l f - l i f e times (23.9 and 43.J hours r e s p e c t i v e l y ) . Referring to the work of C h r i s t i a n and Purves ( 1 8 ) , the trans- d i n i t r a t e was shown to be about twice as unstable thermally as the c i s - d i n i t r a t e at 106°C, but the c i s - isomer reacted more ra p i d l y with 0 » 1 M sodium hydroxide at 100°C i n 5 0 $ aqueous ethanol solution than the trans- isomer. Suspecting thermal decomposition we heated the d i n i t r a t e with a hydrocarbon solvent, 3-methyIneptane, which had almost the same reflux i n g temperature as the p y r i d i n e - d i n i t r a t e mixture. After a forty-eight-hour r e f l u x i n g period, i t was observed that about 3 0 $ of the d i n i t r a t e remained unchanged as against 2 5 $ for the pyridine run. In the 3-methylheptane case, insoluble black 4 8 12- 16 20 Z4- ZQ 3Z 36 4-0 44 48 T I M E I N H O U R S 24 product ( 1 1 $ by weight of d i n i t f a t e used) and a colorless l i q u i d were formed i n the reaction mixture. The black product burned and did not dissolve i n s u l f u r i c acid and N,N-dimethylformarnlde, and was thought to be l a r g e l y free carbon. The colorless l i q u i d was non-flammable and insoluble i n benzene but soluble i n water and believed to be water. In the pyridine run, 9«3$ of a black powder was also formed, but i t was found to be soluble i n con centrated s u l f u r i c acid. It i s most probable that thermal decom pos i t i o n does occur to a large extent, and that i n the case of the pyridine run, the basic media aided i n the polymerization of the d i n i t r a t e and pyridine decomposition products. The presence of small amounts of water ( 1 $ - 3$ by volume of pyridine used) seemed to i n h i b i t the decomposition of the d i n i t r a t e s . Table I shows the re s u l t s at one hour reaction time for the c i s - d i n i t r a t e with pyridine containing 1-3$ by volume of water. With increase i n water content there was a decrease i n d i n i t r a t e decomposition. Less intensely colored reaction mixtures were obtained with an increase i n water content from 1$ to 1 0 $ . This was observed i n runs car r i e d out at 8l°C and at r e f l u x temperatures. The quenching of the pyridine reaction mixture i n excess cold water followed by removal of the unreacted d i n i t r a t e with ether extractions gave the so-called "aqueous-pyridine s o l u t i o n " . On evaporating i t to dryness, an aqueous-pyridine residue was l e f t behind. The y i e l d of t h i s dark material was over twice greater for the trans- than for the c i s - isomer, and increased exponent i a l l y with reaction time (Table I I ) . TABLE I. DECOMPOSITION OF THE DINITRATES Run' Reflux time (nr.) Moles Water added D i n i t r a t e Recovered % Recovered n D 2 i ^ $N** % d i o l 13.15 (CIS-) 1 1 n i l 9 6 . 9 1 4 7 6 3 1 3 . 4 ^ 1 3 . 3 5 2 k n i l 9 3 , 6 1.V763 1 3 . 5 6 3 n i l 70.0 1.4763 -- k* 48 n i l kk-k 1 4 7 6 3 — 5 1 0.0083 9 6 . 6 1.4763 — — 13.22 6 1 0.0170 97-3 1.4764 1 3 . 2 7 7 1 0.031+0 9 8 . . 0 1 . 4 7 . 6 3 — (TRATNS -)... l " ' r " " 1 n i l 9 3 . 9 1.4747 — — 1 3 . 8 4 k n i l 85.4 1.4745; 13.84 — 3 24 n i l 50.8 1-4743 — 9 6 48 n i l 25.5 1.474^ 9 9 Moles of dinitrate/moles of pyridine used = 0 .04 """"" Nitrogen analyses done by the method of Brown and Purves ( l 5 ) and Ma and Zuazaga ( 4 2 ) . Freshly prepared c i s - and trans- d i n i t r a t e s had ni ) 2 4 o I . I4 .763 and nj )24o 1.4743* respectively, and 1 3 . 6 2 , 13.59% N (Theoretically 1 3 . 5 9 # N . ) Reaction mixture quenched i n excess water. 2 6 TABLE II. AQUEOUS PYRIDINE RESIDUE Run Weight Di n i t r a t e (gm.) Reflux time (nr.) Aqueous Pyridine Residue (gm.) (CIS-) 8 l j . , 0 k ' 0 . 1 0 3 . 2 . 1 0 . 1 6 (TRKNS-) i ] + . - 0 £ 0 min. 0 . 0 9 6 i | . 0 7 0 min. 0 . 1 1 7 k..o k . 0 . 3 7 2 k 0 . 3 1 ^ 8 • 1 0 0.14-3 - k 3 . 0 ^ 8 - 0 . 6 1 27 Examination of t h i s material showed the presence of pyridinium n i t r a t e , adipic and succinic acids, and the absence of the d i o l s and the mononitrates. Pyridinium n i t r a t e was shown to be produced only i n the presence of moisture (14). During the present investigation, when the r e f l u x condenser and drying tube were detached from the reaction f l a s h , pyridinium n i t r a t e c r y s t a l l i z e d out immediately on the "wet" upper half of the reaction f l a s k . The formation of adipic acid could be explained on the basis of previous works on thermal decomposition of n i t r a t e and n i t r i t e esters ( 3 8 , 6 8 , 6 9 ) . The decomposition of our n i t r a t e would have undergone the following steps: N I O 2 8 The adipaldehyde i s e a s i l y oxidized by a i r to adipic acid, and would be probably immediately oxidized i n the hot reaction mixture containing d i f f e r e n t oxides of nitrogen (14). The formation of succinic acid should be accompanied with the production of oxalic acid i f an elimination reaction or thermal decomposition occurred. The interference of p y r i  dinium n i t r a t e prevented the detection of the oxalic acid. According to Hughes and Ingold ( 3 7 ), elimination reactions take place i n disubstituted compounds with a x i a l - a x i a l (trans-) and axia l - e q u a t o r i a l ( c i s - ) conformations —- more r e a d i l y i n the former case. Thermal decomposition of esters give o l e f i n s only i n the cases where the conformation of the 1 , 2-substituents are axia l - e q u a t o r i a l ( c i s - ) and a x i a l - a x i a l (trans-), and where a planar t r a n s i t i o n state i s possible. In either case, the reactions probably are: O X C l l i c a n d s u c c i n i c a c i d s 2 9 1 , 3-cyclohexadiene r e a d i l y polymerizes when exposed to l i g h t . Under the oxidative conditions i n the reaction mixture, the diene was probably oxidized to oxalic and succinic acids. In 3-methylheptane with trans-l , 2-cyclohexanedioI d i n i t r a t e at about the same r e f l u x temperature as that of the py r i d i n e - d i n i t r a t e mixture, i t was shown that o x a l i c , succinic and adipic acids were formed as decomposition products. Again, thermal decomposition, elimination and oxidation reactions would account for these products. The reaction products also included some lead-tetra- acetate-oxidizable material which did not correspond to the c i s - and trans- d i o l s . If any d i o l was formed by thermal decom posi t i o n of the d i n i t r a t e , i t may have undergone oxidation to the adipaldehyde and then to the adipic acid stage. The presence of carbonyl compounds i n the pyridine reaction products was demonstrated by the formation of several colored spots with p-anisidiue reagent. Glutaconaldehyde i s known to be produced from pyridine by the oxidative opening of the ring ( 7 1 ) . In acid solution i t has the yellow-brown d i - aldehyde structure and i n the basic media i t i s i n the form of the dark red enolate ion. OHC- CH 2- CH = CH - CHO K OCH = CH - CH = CH-CHO - (acid) + H* (base) In the present case, glutaconaldehyde, i f formed probably polymerized or condensed with the decomposition products from the d i n i t r a t e . 3 0 When the pyridine-reaction mixture was vacuum d i s  t i l l e d at room temperature aft e r one hour of re f l u x i n g , a colorless d i s t i l l a t e was c o l l e c t e d . This solution, when a c i d i f i e d with hydrochloric acid, reacted with a n i l i n e to produce a red solution. Paper chromatography showed the presence of a new red derivative which did not correspond to glutaconaldehyde d i a n l l i d e (71). Phenylhydrasine gave no c r y s t a l l i n e d e r i v a t i v e with the d i s t i l l a t e but heating produced a red color i n d i c a t i n g again that some carbonyl compounds may have been present. The presence of unsaturated compounds and (or) e a s i l y oxidizable low molecular weight aldehydes and alcohols was demon strated by permanganate-carbonate reduction of the d i s t i l l a t e . A c i d i f i c a t i o n of the reduced solu t i o n produced some non-acidic material melting at 130° - 140°C. The d i s t i l l a t e of the 3-methylheptane-dinitrate reaction mixture also showed unsaturation with both bromine and permanganate solutions. Presence of some e a s i l y oxidizable material was also noticed when a small amount of an a c i d i c sub stance pre c i p i t a t e d out of the d i s t i l l a t e a f t e r standing for a few days at room temperature. The reaction with quinoline of the trans- d i n i t r a t e at 165°C produced water and some dark pyridine-soluble polymer. CONCLUSIONS The decomposition of c i s - and trans- 1,2-cyclohex- anediol d i n i t r a t e s by pyridine, 3-methylheptane and quinoline produced o x a l i c , succinic and adipic acids, pyridinium n i t r a t e , water, aldehydes, alcohols, unsaturated compounds, polymeric materials and a gaseous product. The absence of the 2-nitroxy- cyclohexanols and 1,2-cyclohexanediols among the products was noted i n a l l cases. Although water was produced i n the 3-methylheptane and quinoline reactions, i t was not shown to be present i n the pyridine reactions. Its presence Indicated vigorous oxidation conditions i n the reaction mixtures, and also the p o s s i b i l i t y of the formation of other fragmentary products such as formal dehyde, formic acid, g l y o x y l i c acid and carbon dioxide which were not detected. Oxalic acid was not detected i n the pyridine r e a c t i o n products because of the interference of the pyridinium n i t r a t e ; i t was believed to be produced however, together with succinic acid through thermal decomposition and (or) elimination reactions. Adipic acid originated from the ri n g opening of the d i n i t r a t e s by thermal den i t r a t i o n followed by oxidation. The various polymers formed appeared to be secondary decomposition products from the d i n i t r a t e and the pyridine. When a basic media was not present, as i n the 3-methylheptane reactions, carbonization was observed rather than polymerization. The absence of 2-nitroxycyclohexanols and 1,2-cyclo hexanediols could not be attributed to a lack of free proton because of the profound decomposition suffered by both the 3 2 pyridine and the d i n i t r a t e . The conformation of the trans-1.2-cvclohexanediol d i n i t r a t e must be at least p a r t i a l l y a x i a l - a x i a l i n order to explain the production of oxalic and succinic acids. The hydrolysis work of C h r i s t i a n and Purves (18) supported t h i s view. The rates of decomposition depended upon the con formation of the isomers; the trans- d i n i t r a t e decomposed l . S times faster than the c i s - isomer i n pyridine solution. 33 EXPERIMENTAL A. Materials N i t r i c Acid; Red fuming n i t r i c a c i d , supplied by Baker and Adams, was dried by d i s t i l l i n g i n vacuo from twice i t s weight of concentrated s u l f u r i c acid. Pyridine; Reagent-grade pyridine was dried by refluxi n g with technical grade barium oxide and d i s t i l l e d . The f r a c t i o n b o i l i n g between 114° and 115°C was co l l e c t e d and stored over calcium hydride. It was d i s t i l l e d from calcium hydride under anhydrous conditions just before use. Quinoline: Reagent grade quinoline was d i s t i l l e d i n vacuo and the middle f r a c t i o n collected to give a pale yellow l i q u i d , b.p. 1 1 5 ° - 116°C at 18 mm. 3-Methylheptane; Technical grade Bios Laboratory product was washed with concentrated s u l f u r i c acid ( u n t i l the washings were colorless) and then with water. It was dried over anhydrous magnesium sulfate and then over calcium hydride before being d i s t i l l e d . The f r a c t i o n b o i l i n g between 116° and 117°C was used. Hexane-Methanol Chromatography Solvent; Technical- grade hexane was washed several times with concentrated s u l f u r i c acid, then with water, and dried over anhydrous magnesium sulfate . The f r a c t i o n d i s t i l l i n g between 67° and 69°C was saturated with reagent-grade methanol and used i n p a r t i t i o n paper chromatography. 3 4 c i s - and trans- 1 , 2 - Cyclohexanediols: c i s - 1 , 2 - Cyclohexanediol was prepared from cyclohexene by the method of Clark and Owen ( 1 7 ) . It was r e c r y s t a l l i z e d from ethyl acetate and melted c o r r e c t l y at 9 7 ° - 9 8°C. trans- 1 , 2 - Cyclohexanediol was also prepared from cyelohexene by a modification of method of Roebuch and Adkins ( 5 2 ) . R e c r y s t a l l i z a t i o n from ethylacetate yielded a c o l o r l e s s product, m.p. 1 0 2 ° - 1 0 3°C. Barium Methylate; Barium methylate for deacetylation reaction was prepared by r e f l u x i n g 2 5 gm. barium oxide with 5 0 ml. absolute methanol for two hours. The insoluble barium hydroxide was f i l t e r e d o f f , and the f i l t r a t e d i l u t e d to 1 0 0 ml. with absolute methanol. T i t r a t i o n with IN- s u l f u r i c acid established the normality of the solution. Palladized Charcoal Catalyst; The palladium on charcoal catalyst for hydrogenobysis of n i t r a t e groups was prepared by the method of Hartung ( 3 0 ) . Alumina; Merck's acid-washed alumina was used for column-chromatographic separation of n i t r a t e esters. Diphenylamine Reagent; Diphenylamine reagent for testing for the presence of n i t r a t e was prepared after the method of Mulliken ( 4 5 ) . Lead Tetracetate Spray Reagent: A solu t i o n of lead tetraacetate 1 . 0 gm. i n benzene ( 1 0 0 ml.) was shaken with charcoal and f i l t e r e d . The dry paper chromatograma were moistened with a l i t t l e xylene, sprayed with the reagent and dried at room temperature. Wherever glycols were present, the 3 5 lead reverted to the bivalent state whereas the brown lead dioxide pr e c i p i t a t e d on the rest of the paper. White patches on a brown background were considered to be a positive t e s t . p_- Anisidine Spray Reagent; p-Anisidine reagent was prepared by dissolving 5 gm. pure p-anisidine i n 1 6 6 ml. n- butanol, and then adding 3 . 8 ml. of concentrated hydrochloric acid. The chromatogram was dried, then sprayed with t h i s reagent and developed at 1 3 0 ° - 150°C i n an oven for a few minutes. This reagent i s frequently used for detecting aldohexoses, ketohexoses, aldopentoses and uronic acids. Different shades of colors are produced. Bromocresol Green Spray Reagent; Bromocresol green (0.04 gm.) was dissolved i n 9 5 $ ethanol to give a green solution. Thoroughly-dried chromatograms were sprayed with t h i s reagent. Yellow patches on a green background were considered to be posit i v e tests for the presence of acids. Paper-Partition Chromatography; ( 1 ) Organic Acids: The chromatography solvents Butanol-Formic Acid - Water ( 4 : 1 : 5 ) and ( 2 : 1 : 1 ) , Butanol-A c e t i c Acid-Water ( 4 : 1 : 5 ) , and Phenol-Formic Acid-Water ( 7 5 : 1 : 2 5 ) were used for the separation and i d e n t i f i c a t i o n of organic acids present i n the reaction products. ( 2 ) Nitrate Esters: Hexane-Methanol Chromatography solvent was used to separate the n i t r a t e esters. This method was developed i n this laboratory by Michael Jackson. 3 6 B. Syntheses of 1 , 2-Cyclohexanediol D i n i t r a t e s (a) Trans-l , 2-Cyclohexanediol D i n i t r a t e t r a n s - 1 , 2 - Cyclohexanediol D i n i t r a t e was prepared by the method of Soffer and coworkers ( 5 7 ) . t r a n s - 1 , 2 - Cyclo hexanediol was ni t r a t e d by an anhydrous n i t r i c acid, acetic acid and acetic anhydride mixture. The yellow n i t r a t e product was p u r i f i e d by vacuum d i s t i l l a t i i o n to give a c o l o r l e s s , musty- smelling o i l , b.p. 6 6 ° - 67°C at 0 . 0 3 mm. n D 2 ? - 5 1 . 4 7 3 2 Y i e l d = 6 7 $ . (°) c i s - 1 , 2 - Cyclohexanediol D i n i t r a t e The same method of n i t r a t i o n was ca r r i e d out on the c i s - 1 , 2 - cyclohexanediol. The yellowish o i l y product was p u r i f i e d by f r a c t i o n a l d i s t i l l a t i o n to give a c o l o r l e s s , musty- smelling o i l , b.p. 7 4 ° - 76°C at 0 . 0 3 mm. or 1 0 6 ° - 108°C at 1 mm. n D 2 7 , 0 1 . 4 7 5 7 . Hydrogenation of about 1 gm. samples of the trans- and c i s - 1 , 2 - cyclohexanediol d i n i t r a t e s at 40 p . s . i . hydrogen and room temperature using 40 ml. alcohol as solvent and 1 gm. of palladizeefc charcoal as c a t a l y s t , yielded 9 5 $ to 9 8 $ of the th e o r e t i c a l amount of the respective dliols. C. Syntheses of 2-Nitroxycyclohexanols (a) trans- 2 - Nitroxycyclohexanol Twenty-five grams ( 0 . 1 5 m.) of s i l v e r n i t r a t e was dissolved i n 3 1 ml. of dry reagent-grade a c e t o n i t r i l e . The 3 7 temperature of the mixture was lowered to 0°C, and t r a n s - 2 - bromocyclohexanol ( 2 5 gm., 0.14 m.) ( 6 6 ) was added dropwise with gentle swirling. The mixture was then kept at 0°C f o r 48 hours and then at room temperature for another 2 1 hours. The whitish p r e c i p i t a t e was then f i l t e r e d o f f , and the clear solution warmed up to 85°C for 5 minutes. The pr e c i p i t a t e that formed was f i l t e r e d o ff and the f i l t r a t e was extracted with dry ether. The ether extract ( 1 0 0 ml.) was washed with 5 0 ml. water and evaporated. The product remaining was a yellowish o i l . (19 . 2 gm.) On d i s t i l l a t i o n , a colorless o i l was obtained, b.p. 78°C at 0 . 7 5 mm. Y i e l d was 1 1 . 7 gm. or 5 2 $ of t h e o r e t i c a l y i e l d . This o i l c r y s t a l l i z e d out into a white s o l i d with m.p. 2 9 ° . o - 3 1 ° .OC. Hydrogenation of a sample of t h i s product using palladized charcoal as a catalyst gave a co l o r l e s s c r y s t a l l i n e product that melted from 1 0 0 ° to 102°C. R e c r y s t a l l i z a t i o n from ethyl acetate gave a new melting point of 105°C and a mixed melting point with an authentic sample of trans-l , 2-cyclohexanediol was not depressed, (b) c i s - 2 - Nitroxycyclohexanol c i s - 2 - Nitroxycyclohexanol was prepared by the following scheme. 3 8 ( i ) Acetylation of c i s - 1 . 2 - Cyclohexanediol The monoacetate of ci s - l , 2 - c y c l o h e x a n e d i o l was pre pared by the method of Winstein ( 6 5 ) . A colo r l e s s o i l was obtained with b.p. 103°C at 4 . 5 mm. and n D 2 4 * ^ 1 . 4 5 7 2 . This o i l i s understood to be made up mostly of the monoacetate and to have a c i s - orientation. H i ) N i t r a t i o n of c i s - 2 - Acetoxycyclohexanol To 16 . 8 gm. (o . 2 7 m.) of ice- c o l d fuming anhydrous n i t r i c acid was added 1 2 ml. of dry chloroform. This mixture was cooled to about - 1 0°C before 0 . 6 gm. of phosphorus pentoxide was added with s t i r r i n g . To t h i s n i t r a t i o n mixture was then added slowly (dropwise) and with S t i r r i n g the mono acetate ( 2 1 . 0 gm.). Addition took 3 0 minutes, and the reaction mixture was then l e t to stand for 7 5 minutes at 0 ? C. It was then poured into 3 0 0 ml. of ice-cold water, where an o i l y product separated out on the bottom. Two ether extractions of 1 5 0 ml. each was followed by washing with 2 0 ml. of 5% sodium carbonate solution, and twice with 3 5 ml. of water. Drying for h a l f an hour over anhydrous sodium sulfate and then d i s t i l l i n g o f f the ether produced a l i g h t yellow-colored o i l . Vacuum d i s t i l l a t i o n yielded a colorless o i l with b.p. 93°C at 1 . 3 mm. and n D 2 4 * 5 1 . 4 5 3 7 . Y i e l d : 14 . 9 gm. ( i i i ) Deacetylation of the c i s - 1 - Acetoxy - 2-nitroxy- cyclohexane. About 5 . 8 gm. of the nitrated acetate was dissolved i n 1 2 0 ml. of absolute methanol and the solution cooled to 0°C. 39 Then 4 . 3 ml. of 0 . 2 7 5 N barium methylate was added and the solution swirled and l e f t to stand for 24 hours at 0°C. IN- s u l f u r i c acid was added t i l l the solution was a c i d i c to phenol- phthalein followed by reagent grade barium carbonate to neutralize any excess acid present. The solution was f i l t e r e d and then evaporated down to give a yellowish o i l that p a r t l y c r y s t a l l i z e d out. Hexang extraction removed the o i l y product from the c r y s t a l l i n e material that was found to melt at 9 7 ° - 9 8°C. The hexane extract showed two n i t r a t e spots i n hexane- methanol paper chromatography — the unreacted n i t r a t e d acetate at R f 0 . 2 0 , and, what i s considered to be the mononitrate at R f 0 . 5 1 . By pouring t h i s o i l on a dry alumina column and eluting i t with, f i r s t , a benzene-ethanol ( 5 0 0 : 1 ) mixture, then, benzene-ethanol ( 2 0 : 1 ) , the unreacted cis-l-acetoxy - 2-nitroxy- cyclohexane was eluted o f f before the cis - 2-nitroxycyclohexanol. Any c i s - 1 , 2 - cyclohexanediol present would have stayed on the column. On evaporation of the solvent, a yellowish o i l was collected ( 1 . 6 4 gm.) or 3 6 $ . Hydrogenation (40 p . s . i . hydrogen) of a sample of t h i s o i l at room temperature using palladized charcoal as catalyst, yielded a co l o r l e s s c r y s t a l l i n e product with m.p. 9 3 ° - 9 6°C. Mixed melting-point with genuine c i s - 1 , 2 - cyclo hexanediol did not lower the melting point of the l a t t e r . 40 D. Decomposition of c i s - and trans- 1 , 2-Cyclohexanediol Di n i t r a t e s i n Byrldine Solution (a) Preliminary Experiments: 1 , 2 - cyclohexanediol d i n i t r a t e ( 3 gm.) was dissolved i n 3 0 ml. of dry pyridine, and the c o l o r l e s s solution was refluxed at 1 1 8 ° - 120°C i n anhydrous conditions. At about 100°C the solution started to turn yellow, and after f o r t y minutes of reflu x i n g i t was dark amber, and c r y s t a l l i n e p y r i  dinium n i t r a t e and a brownish-red gas appeared i n the r e f l u x condenser. Lengthy re f l u x i n g produced insoluble black residue and more colored gas. When a dry-ice-acetone trap ( - 8 5°C) was attached to the straight water-cooled r e f l u x condenser, only a blue s o l i d (^O^) was c o l l e c t e d . After a given refluxing period, the reaction mixture was allowed to cool to room temperature, f i l t e r e d , and then poured into about 2 5 0 - 3 0 0 ml. of i c e - c o l d water where a heavy o i l separated out i n an amber-colored solution. Several ether extractions of t h i s aqueous-pyridine  solution removed the colored o i l . In several runs, t h i s water- quenching step was omitted. Instead, the pyridine-reaction mixture was d i s t i l l e d at room temperature under vacuo to give a colorless p y r i d i n e - l i k e d i s t i l l a t e and a dark-colored o i l y residue. This o i l y residue was f i r s t checked for the presence of any mononitrate by paper-chromatography using Hexane-Methanol solvent, and then either taken up with some ether and washed with an equal amount of cold water, or immediately chromatographed on an alumina column. 41 Several runs were made with pyridine containing from 0 . 5 $ to 3 * 0 $ by volume of water, and the reaction rates were found to be i n h i b i t e d . With increase i n r e f l u x i n g time, the amount of insoluble jet-black material that formed i n the refluxin g reaction mixture increased. A 3 gm. (0.0.45 m.) sample of the trans- 1,2-cyclohexanediol d i n i t r a t e i n 3 0 ml. dry pyridine after two days of refluxing gave 0 . 2 8 gm. of a black powder that was found to be insoluble i n pyridine, ether, acetone, formamide, dimethylformamide, 3 0 $ NaOH, and concen trated hydrochloric acid, bat was soluble i n cold concentrated °y s u l f u r i c acid to give a dark solution. 74 . 5 $ the trans- d i n i t r a t e reacted and only 0.610 gm. of a h a r d - p l a s t i c - l i k e material was found i n the aqueous-pyridine sol u t i o n a f t e r vacuum d i s t i l l a t i o n of the solvent. A 2.1 gm. (0.0.02 m.) sample of the c i s - l , 2 - c y c l o - hexanediol d i n i t r a t e i n 21 cc (0.26m.) dry pyridine after two days of r e f l u x i n g gave 0.24 gm. of the black p r e c i p i t a t e that was also found to be soluble only i n concentrated s u l f u r i c acid. 5 5 * 6 $ of the c i s - d i n i t r a t e reacted, and only 0.164 gm. of the aqueous-pyridine residue was obtained. (b) I s o l a t i o n of the Unreacted D i n i t r a t e ; About one gram of the o i l y residue, previously obtained by vacuum d i s t i l l a t i o n of the reaction mixture at room temperature, was poured on top of a dry alumina column (1 . 8 x 5 0 cms.) and eluted with ether. The d i n i t r a t e ran with the fro n t , leaving dark yellow, b l u i s h green, and red 42 bands at the top of the column. Normally i t took 2 5 - 3 0 minutes of dripping time for a l l the d i n i t r a t e to come through. After a lapse of another 3 0 minutes, any mononitrate present would begin coming through too. The ether was then removed by vacuum d i s t i l l a t i o n at room temperature to give a colorless o i l y residue (the d i n i t r a t e ) which was checked as to i t s r e f r a c t i v e index and nitrogen values, and d i o l content. (c) Fractionation of the Aqueous-Pyridine Residue: The reaction mixture was d i l u t e d with cold water and extracted with ether to remove the unreacted d i n i t r a t e . Evap oration of the aqueous-pyridine solution at 40° - 45°C (bath) l e f t a dark-brown amorphous residue whose weight increased exponentially with reaction time. The material was completely soluble i n methyl alcohol, and over bQ% soluble i n acetone or hot water. Most of the material could be dissolved by f i r s t extracting i t with acetone and then hot water, the f i n a l residue was soluble i n pyridine. Most of the color was retained i n the aqueous and pyridine extracts. These fr a c t i o n s were studied chromatographically. The colored extracts were concentrated i n vacuo oniihe steam bath to a volume of 5 - 10 ml and then spotted on a Whatman No. 1. chromatographic paper, and eluted with d i f f e r e n t solvents. ( i ) Butanol-Ethanol-Ammonia-Water Solvent (40:10:1:49) Between seven to nine blue, purple, r e d , green and yellow spots showed up under u l t r a - v i o l e t l i g h t from both the c i s - and trans- runs. Diphenylamine reagent brought out only 4 3 the pyridinium n i t r a t e (R f 0 . 2 6 ) , and the p-anisidine-H61 reagent exposed two spots f o r Run 5 ( 5 0 min. refluxing) — — a reddish-brown spot at R f 0 . 2 6 , and a yellowish-brown spot at R f 0.46. The reagent was found to have no effect on the pyridinium n i t r a t e . An aqueous-pyridine residue obtained after four hours of ref l u x i n g did not give any spottings with the p-anisidine reagent, but showed eight to nine spots of various colors under u l t r a - v i o l e t l i g h t . Bromocresol green also picked up a strong acid spot just below the st a r t i n g front. Run 3 ( c i s - d i n i t r a t e ) , after 48 hour re f l u x i n g period, gave with bromocresol green strong acid spots at Rf 0.10 and 0 . 2 0 (the l a t t e r was also p o s i t i v e to diphenylamine reagent and corresponded to pyridinium n i t r a t e ) , a weak acid spot at R f 0 . 3 3 and a strong basic spot (blue patch) at Rf 0.42. A corresponding acetone extract of Run 1 ( t r a n s - d i n i t r a t e ) , a f t e r an hour of re f l u x i n g , showed a weak acid spot at R^ 0 . 1 2 , and a strong one at Rf 0.22 (also positive to diphenylamine t e s t and corresponding to pyridinium n i t r a t e ) and a weak acid spot at R f 0.44. Nothing was picked up with lead tetraacetate spray, ( i i ) Butanol-Acetic-Acid-Water Solvent (2:1:1) p-Anisidine reagent brought out two spots for Run 5 ( 5 0 min. refluxing) and four spots for Run 6 ( 7 0 min. r e f l u x i n g ) . The Rf values were 0 . 2 6 (dark red); 0.62 (yellowish-brown), 0 . 7 7 (yellowish-brown) and 0.91 (dark red). The R f values 0 . 6 2 and 0 . 7 7 were both found i n the two runs. U l t r a v i o l e t l i g h t showed between four to f i v e spots, and the diphenylamine reagent picked up the pyridinium n i t r a t e @ Rf 0.20. Bromocresol green, however, showed a strong acid spot at R^ 0 . 8 4 corresponding to adipic acid (Run 8 , 10 hr. refluxing) ( i i i ) Butanol-Acetic Acid Water Solvent ( 4 : 1 ;5) Acetone extract of Run 8 ( 1 0 hr. refluxing) and the aqueous extract of Run 4 ( 4 8 hr. refluxing) both gave strong acid spots with bromo-cresol green at Rf O . 8 3 corresponding to adipic acid. A weak acid spot appeared at R^ 0 . 7 3 corres ponding to succinic acid. The presence of any oxalic acid was camoflaged by a c i d i c pyridinium n i t r a t e . (iv) Phenol-Formic Acid-Water Solvent (75:1:25)  (Upward Blow) For acetone extract of Run 8 and aqueous extract of Run 4 , strong acid spots were detected with bromo-cresol green at Rf 0 . 7 4 , corresponding to adipic acid, and weak acid spots at Rf 0 . 6 3 j corresponding to succinic acid. Oxalic acid, i f present, should show up at Rf 0 . 3 2 , but again a c i d i c pyridinium n i t r a t e i n t e r f e r r e d . (v) Xylene-Methyl-ethyl-ketone-Water Solvent ( 1 : 1 : 1 ) In the aqueous extract of Run 4 ( 4 8 hours r e f l u x i n g ) , lead-tetraacetate reagent picked up only a narrow white streak extending from the spotting l i n e . Standard trans- and c i s - cyclohexane, 1 , 2 - d i o l s spottings did not correspond with that streak. Bromo-cresol green, however, showed a heavy yellow streak extending almost half-way down the paper. A standard pyridinium n i t r a t e spot did not move from i t s o r i g i n a l spotting position and was detected by the diphenylamine reagent. 45 (vi) Butanol-Formic acid-Water Solvent (4:1:5) Aqueous extract of Run^4 showed a strong acid spot at R f 0 . 8 7 , and a weak one at R f 0 . 7 6 corresponding to adipic and succinic acids respectively. Acidic pyridinium n i t r a t e again interfered i n the detection of any oxalic acid. (d) I s o l a t i o n of the Mononitrate One gram sample of the colorless c i s - 1,2-eyclo- hexanediol d i n i t r a t e was dissolved i n 10 ml. of dry pyridine, and the solution was well stoppered and l e f t to stand for 3 3 days at room temperature. Samples were taken out after the f i r s t , second, and t h i r d hour, and then at twenty-four periods, and chromatographed against standard d i n i t r a t e and mononitrate i n hexane-methanol solvent. No mononitrate or d i o l was detected at any time by diphenylamine reagent and lead tetraacetate. After 3 3 days, the s o l u t i o n became orange- yellow i n color and contained some pyridinium n i t r a t e . About 0 . 3 gm. samples of f r e s h l y d i s t i l l e d trans- 1,2-cyclohexanediol d i n i t r a t e were dissolved i n 3 ml. of freshly d i s t i l l e d pyridine containing from 0% to 10$ of water by volume. These were heated at 81°C for 4 days, and samples taken out at various time i n t e r v a l s and chromatographed i n hexane-methanol solvent. No mononitrate was ever detected. The sample containing dry pyridine became yellov/ish i n 45 minutes, reddish-brown i n 48 hours, and dark-amber after 9 6 hours. Samples containing water were a l l l i g h t e r i n color after 9 6 hours. 46 About 3 gm. of f r e s h l y prepared trans- 1 , 2-eyclo- hexanediol d i n i t r a t e was refluxed with 3 0 ml. pyridine con taining 2 5 $ by volume of water. After a 6 0 minute period, the solution turned only yellow i n color, and paper chroma tography showed no mononitrate. When 3 0 ml. of BaO-dried pyridine was decanted o f f dry potassium hydroxide p e l l e t s and refluxed with 3 gm« of trans- 1 , 2-cyclohexanediol d i n i t r a t e for an hour, no mononitrate was detected i n the residual o i l , after the reaction mixture was vacuum d i s t i l l e d at room temperature. But, with the addition of a small amount of water (1 - 3 $ by volume) followed by refluxing for ann hour, some mononitrate was detected i n the residual o i l . This was shown by chromatographing the r e s i d u a l o i l against standard trans- 1 , 2-cyclohexanediol d i n i t r a t e ( H F 0 . 8 0 ) and trans- 2 nltroxycyclohexanol (Rf 0 . 3 3 ) i n hexane- methanol. Alumina column chromatography using dry ether as eluant could give a good separation of the mononitrate from the d i n i t r a t e i n the residual o i l . About 1 gm. sample of the residual o i l was poured on top of a dry alumina column ( 1 . 8 x 5 0 cm.) and dry ether added. The d i n i t r a t e flowed with the front, and was washed o f f i n about 3 0 minutes, while the mono ni t r a t e only appeared a f t e r an i n t e r v a l of 3 0 to 40 minutes. Diphenylamine reagent was used to check for the appearance and disappearance of the n i t r a t e s . (e) Examination of the D i s t i l l a t e from the Reaction Mixture; About 4.1 gm. of trans- 1 , 2-cyclohexanediol d i n i t r a t e 4 7 was refluxed for 5 0 minutes with 40 ml. of Analar Reagent pyridine that was not previously dried over barium oxide. Then the reaction mixture was d i s t i l l e d at 30°C and reduced pressure to give a colorless d i s t i l l a t e that smelled strongly of pyridine. To 3 ml. of t h i s d i s t i l l a t e was added some concen trated hydrochloric acid to make the sol u t i o n a c i d i c . Then about0.2 ml. of fre s h l y d i s t i l l e d , c o l o r l e s s a n i l i n e was added. The solution turned pink immediately. This mixture was chroma- tographed i n Butanol-Water solvent against genuine glutaconal- dehyde dianihide-hydrochloride ( 7 1 ) . The l a t t e r ran at Rf 0 . 7 5 as an reddish-orange spot, while the former as a red spot at R f 0 . 4 5 . To 2 ml. of the d i s t i l l a t e , about 4 ml. of g l a c i a l acetic acid was added t i l l the solution was a c i d i c and then about 1 ml. of phenylhydrazine solution. The solution turned yellow, and heating just below the b o i l i n g temperature turned i t red. No c r y s t a l l i z a t i o n occurred i n the f r i g i d a i r e overnight. The d i s t i l l a t e was found to reduce 1%- potassium permanganate i n 2% sodium carbonate slowly at room temperature. To 20 ml. of the d i s t i l l a t e at 40° - 50°C was added slowly about 20 ml. of t h i s 1% permanganate-carbonate solution. When the decolorization seemed to have stopped, the manganese dioxide was f i l t e r e d o f f . Concentrated hydrochloric acid was then added t i l l the solution was a c i d i c ; Some c r y s t a l l i n e material appeared as a suspension i n the yellowish solution. Ether extraction removed the c r y s t a l l i n e suspension and most of the yellowish color. The 48 evaporation of the ether extract yielded a mixture of white crystals and orange-colored powder. ( 0 . 1 2 5 gm.) This material melted and burned when heated leaving a charred mass. Chroma tography i n Butanol-Water gave a yellowish spot at R f 0.84 and an acid spot at R f 0.04 (standard succinic, glutanic and adipic acids had higher R f values). When some of the ether extract of t h i s c r y s t a l l i n e material was added to an aqueous-pyridine solution, some l i g h t , f l a k e - l i k e , golden c r y s t a l s appeared, which after f i l t r a t i o n melted at 130° to 140°C, and were found not to be a c i d i c . 49 E. Decomposition of trans- 1,2-Cyclohexanediol D i n i t r a t e  i n 3-lfethylheptane Solution (a) Preliminary Experiments: trans- 1,2-Cyclohexanediol d i n i t r a t e ( 1 . 9 9 gm.) was dissolved i n 2 5 ml. 3-methylheptane at room temperature, and the c o l o r l e s s mixtures/was refluxed at 1 1 9 ° - 120°C gently for 40 hours i n anhydrous conditions. Immediately a brownish-red gas that smelled of nitrogen dioxide was evolved. After eight hours, the solution became only s l i g h t l y yellow and some co l o r  less droplets were noticed to condense out with the 3-methyl heptane i n the cooler part of the r e f l u x condenser. Next morning, a coating of black, insoluble material appeared adhering to the bottom and sides of the reaction f l a s k , together with some col o r l e s s c r y s t a l l i n e material i n the condenser. This c r y s t a l l i n e product was a c i d i c to bromocresol green. With pro longed refl u x i n g more insoluble black residue formed. After 48 hours, the reaction mixture was swirled up, and decanted from the insoluble black residue. This was then washed twice with small amounts of 3-methylheptane, vacuum-dried at room temperature, and then extracted with 3 0 ml. pyridine, and again with an a d d i t i o n a l 20 ml. i n order to remove the l a s t trace of color. The black residue was a i r - d r i e d overnite and weighed. (0.22 gm.) It was found to be insoluble i n acetone, alcohol, ether, N,N-dimethylformamide, 3 0 $ - NaOH and concentrated s u l f u r i c acid. The red-colored pyridine extract was evaporated down 5 0 at 4 5 ° - 50°C to give a dark gummy material. ( 0 . 0 9 0 gm.) This substance was extracted with a t o t a l of 5 0 ml. of hot water, and the extracts evaporated down at 4 5 ° - 50°C to give a yellow o i l y material, which, after standing overnite i n vacuo and over phosphorous p&ntoxide, p a r t i a l l y c r y s t a l l i z e d out ( 0 . 0 5 0 ) gm.) Paper chromatography of t h i s material i n Butanol- Acetic Acid-Water ( 4 : 1 : 5 ) showed the presence of three acids that corresponded to oxalic (R f 0 . 2 6 ) , succinic (R f O . 7 6 ) , and adipic (Rf 0 . 8 4 ) . If an ether instead of a pyridine extraction was carried out on the black residue, followed by an aqueous extraction of the ether extract, then the aqueous extract would be almost c o l o r l e s s . On evaporation to dryness at 4 5 ° - 50°C, almost co l o r l e s s c r y s t a l l i n e material was obtained. Chromato graphy i n Phenol-Formic Acid-Water ( 7 5 : 1 : 2 5 )(upward flow) yielded three acid spots corresponding again to oxalic (Rf 0 . 3 2 ) , succinic (Rf 0 . 6 1 ) , and adipic acid (R f 0 . 7 5 ) . Chromatography i n Xylene-Methylethylketone-Water ( 1 : 1 : 1 ) , and development of the paper chromatogram with lead tetraacetate spray reagent revealed a white streak at Rf 0 . 1 3 , whereas genuine c i s - and trans- d i o l s ran at Rf 0 . 3 0 and Rf 0 . 2 0 respectively. (b) I s o l a t i o n of the Unreacted D i n i t r a t e : The decanted yellow reaction s o l u t i o n from the black residue was d i s t i l l e d at 6 5 ° - 70°C at 8 0 mm. to give a co l o r l e s s d i s t i l l a t e and a yellowish o i l y residue. The l a t t e r weighed 1 . 4 3 5 gm., and when chromatographed i n Hexane-Methanol solvent, showed, besides the unreacted d i n i t r a t e , trace amounts of the trans- 2-nitroxyeyclohexanol. This o i l y residue (1.184 gm.) was put on an alumina column (1.8 x 5 0 ) cms. and eluted with dry ether. The d i n i t r a t e t r a v e l l e d with the front leaving the yellow-colored material behind. On evaporation of the ether solution, 0 . 5 7 2 gm. of a c o l o r l e s s o i l was l e f t behind. Chromatography showed the presence of the d i n i t r a t e only. n D 2 4 * 5 = 1.4675 (should be about 1.4745 i f pure d i n i t r a t e ) . This o i l was then subjected to high vacuum of 3 mm. at 60°C for half an hour, and then for an hour at 2 mm. at room temperature. Weighing gave (0.497 gms.) and n j ) 2 4 * ^ = 1.4719. A 0.468 gm. sample of the o i l was then hydrogenated with 5 0 ml. ethanol and 1 gm. palladized charcoal at 48 p . s . i . of hydrogen at room temperature. After 5 hours the colorless solution showed no n i t r a t e t e s t with diphenylamine reagent. It was f i l t e r e d , washed, and evaporated down to dryness at 45° - 50°C. Light-brown c r y s t a l s formed. After drying i n vacuum over phosphorus pentoxide, the y i e l d was 0.278 gm. and m.p. 96° - 100°C. After d i s s o l v i n g these c r y s t a l s i n e t h y l - acetate followed by f i l t r a t i o n , washing and evaporation, a new y i e l d of 0 . 2 6 3 gm. of c o l o r l e s s c r y s t a l s was obtained m.p. 98° - 101°. (100$ d i o l y i e l d ) . Mixed melting points with genuine trans- d i o l gave m.p. 103°-4° . P u r i f i c a t i o n with charcoal, followed by three consecutive f r a c t i o n a l c r y s t a l  l i z a t i o n s only yielded material of m.p. 1 0 3 ° - 104°C. On the basis of hydrogenolysis, then, 30.2$ of the trans- 1,2-cyclo- hexandiol d i n i t r a t e remained unreacted. 5 2 (c) Examination of the D i s t i l l a t e from the Reaction  Mixture: trans- 1 , 2-Cyclohexanediol d i n i t r a t e ( 2 . 6 2 gm.) dissolved i n 3 0 ml. 3-methylheptane was refluxed at 120°C for 8 8 % hours. The reaction solution was then decanted o f f the black residue, and d i s t i l l e d at 6 5 ° - 70°C and 8 0 mm. To t h i s d i s t i l l a t e was added bromine t i l l the color stopped being discharged. About 0 . 1 ml. of l i q u i d bromine was used. The co l o r l e s s solution was then evaporated o f f at 6 5 ° - 70°C and 6 0 mm. to leave a l i g h t yellow, medicine-smelling o i l ( 0 . 0 7 2 gm.). 3rMethylheptane did not discharge the bromine color. In an e a r l i e r run, the d i s t i l l a t e was found to deposit a small amount ( 1 mg.) of white c r y s t a l l i n e material after standing stoppered for a few days at room temperature. These c r y s t a l s were a c i d i c to bromocresol green. Baeyer's test for unsaturation was then c a r r i e d out. To 1 ml. of the d i s t i l l a t e was added a drop of 2% potassium permanganate solution and shaken up. The colour of the permanganate was discharged immediately. Several more drops were also decolorized. 3-methylheptane did not show any decolorizing e f f e c t s . 5 3 F. Decomposition of trans- 1 , 2-Cyclohexanediol D i n i t r a t e  i n Quinoline Solution; trans- 1 , 2-Cyclohexanediol d i n i t r a t e ( 0 . 6 gm.) was mixed with 6 cc of quinoline, and the temperature of the mixture was raised to 165°C within the f i r s t hour, and main tained at 1 6 0 ° - 165°C t i l l the end of the second hour. During that time some c r y s t a l l i n e material c r y s t a l l i z e d out i n the condenser, and a colorless insoluble l i q u i d was seen to r e f l u x i n the condenser. No mononitrate nor d i n i t r a t e was detected i n the mixture by paper chromatography. D i s t i l l a t i o n at 160°C yielded a few droplets of a colorless l i q u i d which was found to be insoluble i n quinoline and benzene, but soluble i n water. Heating of 2 . 6 2 gm. of trans- 1 , 2-cyclohexanediol d i n i t r a t e i n 2 5 ml. of quinoline for 7% hours between 145° - 165°C yielded some blue s o l i d ( N 2 O 3 ) i n a dry-ice trap ( - 8 5°C). No d i o l nor mononitrate was detected i n the black reaction mixture — only the unreacted d i n i t r a t e . About 1 2 0 cc of sodium-dried henzene was added to the reaction mixture, and the heavy p r e c i p i t a t i o n occurred. Aseotroping of t h i s mixture for 6 hours yielded 0 . 6 ml. of a colorless l i q u i d which showed a l l the properties of water. On f i l t e r i n g the benzene-quino- l i n e solution, 1 . 0 7 gm. of a dark-brown material was c o l l e c t e d . This substance was insoluble i n water, s l i g h t l y soluble i n acetone, and very soluble i n pyridine. BIBLIOGRAPHY 1 . A l l i n g e r , N.L., Exp., 1 0 , 3 2 8 , ( 1 9 5 4 ) . J. Org. Chem. 2 1 , 915, (1956). 2 . Angelic A., Z. ges. Schiess-Sprengstoffw. 17 : 1 1 3 , 1 9 2 2 . 3 . Adams. G. and Bawn, C.E., Trans. Far. S o c , 4 £ , 494, (1949). 4 . Baker, J.W. and Nathan, W.S., J. Chem. S o c , 2 3 6 , (1936). 5 . Baker, J.W. and Easty, D.M., J. Chem. S o c , 1193, ( 1 9 5 2 ) . 6. Baker, J.W. and Easty, D.M., Nature, 166, 156, ( 1 9 5 0 ) . 7. Barton, D. Exp. 6, 316, (1950). 8 . Barton, D. Quart. Revs., 1 0 , 44, (1956). 9. Barton, D. J. Chem. S o c , 1197, (1943). 1 0 . Bastlensen, 0 . and Hassel, 0 . Tidsskr. Ktf.enii Berguesen Met. 6 , 9 6 , ( 1 9 4 6 ) . 1 1 . B e l l , D.J.;-afid Friedmann, E. and Williams, S., J. Chem. S o c 2 5 2 , (1937). 1 2 . Bowering, W. and Hayward, L.D. MSc Thesis Univ. of B r i t . Col. 1956. 1 3 . Brook, A.G. and Wright, G.F. Can. J . Chem. 29, 308, (1951). 14. Brown, J.R. and Hayward, L.D. Can. J. Chem. 1 3 , 1737, ( 1 9 5 5 ) . 1 5 . Brown, R.K. and Purves, C.B. Pulp and Paper Mag. of Canada, May (1947). 16. Brenton, C.A. and F r e i , Y.F. J. Chem. S o c , I 8 7 2 , (195D. 1 7 . Clark, M.F. and Owen, L.N. J. Chem. S o c , 3 1 8 , ( 1 9 4 9 ) . 18. C h r i s t i a n , W.R. and Purves, C.B. Can. J. Chem. 2 2 , 9 2 6 , (195D. 19. C r i s t o l , S.J. and Franzus, B.J. Am. Chem. S o c , £2, 2 4 8 8 (1957). 2 0 . C r i s t o l , S.J. and Weber, J. and B r i n d e l l , M.J. Am. Ghem. S o c , Z§, 5 9 8 ( 1 9 5 6 ) . 2 1 . Crossley, A.W. J. Chem. S o c , 1403, (1904). 2 2 . Day, J.N. and Ingold, C.K., Trans. Far. Soc. 32, 6 8 9 , (1941). 2 3 . E l r i c k , D.E.,«ftd Marans, N.S. and Preckel, R.F. J. Am. Chem. Soc. 26, 1 3 7 3 , (1954). 24. English, J. and Barber, J.W. J. Am. Chem. Soc. 2i» 3 3 1 0 , (1949). 2 5 . Falconer, E.L. and Purves, C.B., J. Am. Chem. Soc. 79, 5 3 0 8 ( 1 9 5 7 ) . 2 6 . Giannini, G. Gazz. Chem. I t a l . £4, 7 9 , (1924). C.A . 1 8 , 2 8 1 0 , (1924). 2 7 . Gibson, D.T. and MacKeth, A.K. J. Chem. S o c , 119, 4 3 8 ( 1 9 2 1 ) . — 2 8 . Gladding, E.W. and Purves, C.B. J.Am. Chem. S o c 6 6 , 7 6 , (1944). 2 9 . Hassel, 0 . Research (London) 3 , 5 0 4 , ( 1 9 5 0 ) . 3 0 . Hartung, W.J. J.Am. Chem. S o c , 6 8 , 1 6 2 1 (1946) 3 1 . Hayward, L.D., J. Am. Chem. S o c , 22> 1974 ( 1 9 5 D . 3 2 . Hayward, L.D. Can. J. Chem., ^ 2 , 1 9 , ( 1 9 5 4 ) . 3 3 . Hine, J. and Brader, W.J. J.Am.Chem.Soc, 2Z» 3 6 1 , ( 1 9 5 5 ) . 34. Hockett, R.C., J. Am. Chem. S o c , 68, 9 3 0 , (1946). 3 5 « Jackson, M. Private communication. 3 6 . K i l p a t r i c k , M. and Morse, J.G. J.Am. Chem. S o c , 75. 1846, (1953). 3 7 . Klyne, W. Progfess i n Stereochemistry. V o l . 1 . Acad. Pres. Inc., New York, 1 9 5 4 . 3 8 . Kuhn, L.P. and De Angelis, L. J. Am.Chem. S o c , 26, 3 2 8 , (1954). 3 9 . Lawe, E.S. J. Chem. S o c , 1 1 7 2 , ( 1 9 5 3 ) . 40. Levy, S.B. J. Am. Chem. S o c , 2i, 3 2 5 4 , 3 7 9 0 , ( 1 9 5 4 ) . 41. Lucas, G.R. and Hammett, L.P. J.Am. Chem. S o c , 64, 1928, (1942). ~~ 42. Ma, T.S. and Zuazaga, G. Ind. and Eng. Chem., Anal. Ed., 14, 280, (1942). 43. McCasland, G.E., J . Am. Chem. S o c , £3» 2293, (195D. 44. McKeown, G.G. and Hayward, L.D. Can. J. Chem., 33, 1392, (1955). 45. Mulliken-Huntress, "Mannal of the I d e n t i f i c a t i o n of Organic Compounds", M.I.T., p. I63, (1937). 46. Ness, A.T.,e»4 Harm, R.M. and Hudson, C.S. J. Am. Chem. S o c , 66, 1901, (1944). 47. Oldham, J.W. and Rutherford, J.K. J.Am. Chem. S o c , 54, 366, (1932). 48. Pascual, J. J. Chem. S o c , 1943, (1949). 49. P i t z e r , K.S. and Beckett, C.W.T. Am. Chem. S o c , 6£, 977, (1947). 50. P h i l l i p s , L. Nature, I65, 564, (1950). 51. Pollak, P.I. and Curtin, D.V., J. Am. Chem. S o c , 72, 961, (1950). 52. Roebuck, A. and Adkins, H., Org. Syn. Vol. I l l , p. 217. 53. Rooney, C.S. Ph.D. Thesis, McGill Univ. 1952. 54. Ryan, H. and Casey, M.T. Scien. P r o c Royal. Dublin S o c , i&, 101, (1928-30). 55. Segal, G.H. Ph.D. Thesis McGill Univ. 1946. 56. Smith, A.S. and Byrne, P.P., J. Am. Chem. S o c , 2£, 4406, (1950). 57. Soffer, L.M.,^Gd-Parrotta, E.W. and DiDomenico, J . , J. Am. Chem. S o c , £4, 5301, (1952). 58. Swan, E.P. B.A. Thesis, Univ. of B r i t . Col. 1952. 59. Tichanowitsch, S.Z., J. Chem. Pharm., 482, (1864). J. F o r t s e h r i t t e Chem., 582, (1864). 60. Tipson, R.S.,-eftd-Clapp, M.A. and Cretcher, L.J., J . Org. Chem. 12, 133, (1947). 6 1 . Tipson, R.S. and Cretcher, L . H . , J . Org. Chem., 8 , 9 5 , ( 1 9 4 3 ) . 6 2 . T u l i n s k i e , A. J. Am. Chem. S o c , Zli 3 5 5 2 , ( 1 9 5 3 ) . 6 3 . Wigner, J.H. Ber., 3 6 , 7 9 4 , ( 1 9 0 3 ) . 6 4 . Winstein, S. and Buckles, R.E. J. Am. Chem. S o c , 6 4 , 2 7 8 0 , ( 1 9 4 2 ) . 6 5 . Winstein, S. and Buckles, R.E. J. Am. Chem. S o c , 6 4 , 2 7 8 7 , ( 1 9 4 2 ) . 6 6 . Winstein, S.,-and-Hess, H.V. and Buckles, R.E., J . Am. Chem. S o c , 6 4 , 2 7 9 6 , ( 1 9 4 2 ) . 6 7 . Winstein, S. ,-aftd- Grunwald, E. and Buckles, R.E. J. Am. Chem. S o c , 20» 8 l 6 , ( 1 9 4 8 ) . 6 8 . Welfrom, M . L . J . Am. Chem. S o c , 22> 6 5 7 3 , ( 1 9 5 5 ) . 6 9 . Wolfrom, M . L . J. Am. Chem. S o c , 2 £ , 4 6 9 5 , ( 1 9 5 6 ) . 7 0 . Wright, I. B.A. Thesis Univ. of B r i t . Col. 1 9 5 7 . 7 1 . Zincke, T. and Heuser, G. and Holler, W. Ann. 3 3 3 : 2 9 6 , ( 1 9 0 4 ) . 

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.831.1-0062227/manifest

Comment

Related Items