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The methylation of sugar mercaptals Yates, Keith 1957

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THE METHYLATION OP SUGAR MERCAPTALS by KEITH YATES B.A., U n i v e r s i t y  of B r i t i s h Columbia, 19^6  A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE  i n the Department of Chemistry  We accept t h i s t h e s i s as conforming t o the r e q u i r e d standard  THE. UNIYERSITY OF BRITISH COLUMBIA October, 19^7  ii  ABSTRACT I t was r e p o r t e d i n 1934  by L i e s e r and  Leckzyck  that D-glucose d i e t h y l mercaptal could he s e l e c t i v e l y methylated by use of methyl i o d i d e and  s i l v e r oxide at 0°C.  e x c l u s i v e l y 2-0-methyl-D-glucOse d i e t h y l m e r c a p t a l i n yield.  to g i v e  5>2$  They stated that the mercaptals of D-galactose.-,.  L-arabinose, D-xylose s i m i l a r way  and L-rhamnose f a i l e d  and i s o l a t e d no p r o d u c t s . to determine  to r e a c t i n a  The. present  Investi-  g a t i o n was  undertaken  to what extent these  statements  are correct,, and i f m e t h y l a t i o n does occur w i t h  the mercaptals of other sugars,,, to determine the nature of the methylated p r o d u c t s . i f r e a c t i o n predominates  I t was  a l s o of i n t e r e s t t o  determine  at any one p o s i t i o n as i n D-glucose  mercaptal. The o r i g i n a l o b s e r v a t i o n s of L i e s e r and  Leckzyck  were s u b s t a n t i a l l y confirmed by a r e p e t i t i o n of t h e i r e x p e r i ments.  The p r e s e n t work, however, has shown t h a t some  m e t h y l a t i o n does occur w i t h mercaptals other than t h a t of D-glucose but to a much s m a l l e r extent, and t h a t t h i s i s p a r t l y due to the i n s o l u b i l i t y of these; mercaptals i n methyl iodide. T e t r a h y d r o f u r a n was  found to be a s u i t a b l e  methyl-  a t i o n s o l v e n t i n which the d i e t h y l mercaptals of D-glucose, D-galactose, L-arabinose and D-mannose have comparable bility.  These mercaptals were methylated  a m o d i f i c a t i o n of L i e s e r * s procedure.  solu-  i n t h i s s o l v e n t by  I n v e s t i g a t i o n of the  iii  p r o d u c t s by paper chromatography i n d i c a t e d t h a t a l l f o u r gave similar results.  Further  there d i d not appear to. be any s i g n i -  f i c a n t d i f f e r e n c e i n the r e a c t i o n s when they were c a r r i e d out at 3 ° , 2 2 ° , and f?0°C. exploratory  scale.  These experiments were a l l on an  S u i t a b l e c o n d i t i o n s were e s t a b l i s h e d f o r  l a r g e r s c a l e methylations  and separations  of products„  One such l a r g e s c a l e m e t h y l a t i o n carried  out on D-gluCose d i e t h y l mercaptal and the p r o d u c t s  hydrolysed  and separated  chromatography. arated  and s e p a r a t i o n was  as the f r e e sugars by means of column  S i x d i s t i n c t methylated glucoses  were sep-  showing that the r e a c t i o n i s by no means as s e l e c t i v e  when t e t r a h y d r o f u r a n  i s used as r e a c t i o n s o l v e n t .  The l a r g e s t  p r o d u c t , but no longer dominantly so., was p o s i t i v e l y as the 2-0_-methyl d e r i v a t i v e , again g r e a t e s t at the 2 - p o s i t i o n .  identified  showing t h a t r e a c t i v i t y i s  T h i s was found t o be the o n l y  monomethyl e t h e r produced. A second l a r g e s c a l e m e t h y l a t i o n carried  out In an e x a c t l y s i m i l a r manner on D-^mannose d i e t h y l  mercaptal.  E i g h t d i s t i n c t methylated mahnoses were  with the extent above. tified  and s e p a r a t i o n was  of m e t h y l a t i o n  being  comparable with  separated that  Two major monomethyl p r o d u c t s were i s o l a t e d and idenby p e r i o d a t e  o x i d a t i o n s t u d i e s and t h e i r osazones as  the 6-p_-methyl and ^-0_-methyl d e r i v a t i v e s .  The r e s u l t s i n d i -  cate that the 6 - p o s l t i o n i s most r e a c t i v e i n D-mannose d i e t h y l mercaptal. A third  s i m i l a r methylation  of L-arabinose d i e t h y l  m e r c a p t a l , f o l l o w e d by s e p a r a t i o n of products by a combination  iv of column and paper chromatography, y i e l d e d seven methylated  arabinoses.  distinct  There were no major monomethyl  p r o d u c t s , r e a c t i o n appearing to have gone l a r g e l y to the dimethyl stage.  Three monomethyl arabinoses were, separated  i n n e g l i g i b l e amounts and could not be i d e n t i f i e d .  Reaction  a p p a r e n t l y does not predominate at any one p o s i t i o n i n Larabinose d i e t h y l m e r c a p t a l . P r e l i m i n a r y experiments mercaptal nature.  diethyl  i n d i c a t e d m e t h y l a t i o n t o be of a h i g h l y random An e x p l o r a t o r y s e p a r a t i o n o f p r o d u c t s showed t h a t no  one monomethyl ether predominated. and  on D - g a l a c t o s e  s e p a r a t i o n was not repeated  The l a r g e s c a l e m e t h y l a t i o n  on t h i s  mercaptal.  Of the compounds i n v e s t i g a t e d , unusual  reactivity  of the 2-hydroxyl group i s o n l y c l e a r l y manifested by Dglucose m e r c a p t a l .  No marked r e a c t i v i t y of t h i s p o s i t i o n i s  shown by the other mercaptals, although t h e r e i s evidence that the 6- and 5~hydroxyls of D-mannose m e r c a p t a l are. unusually r e a c t i v e .  In p r e s e n t i n g the  t h i s thesis i n p a r t i a l fulfilment of  requirements f o r an advanced degree at the U n i v e r s i t y  o f B r i t i s h Columbia, I agree t h a t  the L i b r a r y s h a l l make  it  and study.  f r e e l y available f o r reference  I further  agree t h a t permission f o r e x t e n s i v e copying o f t h i s t h e s i s f o r s c h o l a r l y purposes may be granted by t h e Head o f my Department o r by h i s r e p r e s e n t a t i v e .  I t i s understood  t h a t copying o r p u b l i c a t i o n o f t h i s t h e s i s f o r f i n a n c i a l gain  s h a l l not be allowed without my w r i t t e n  Department o f  CHEMISTRY  The U n i v e r s i t y o f B r i t i s h Vancouver 8, Canada. Date  Columbia,  September- 10th.. 1957.  permission.  y  ACKNOWLEDGE]^ ICT  Thanks are extended, t o Dr. G..G.S. Dutton f o r h i s p a t i e n t and invaluable, d i r e c t i o n  of t h i s r e s e a r c h , and  a l s o t o the. N a t i o n a l Research C o u n c i l f o r f i n a n c i a l tance.  assis-  yi TABLE OF CONTENTS Page HISTORICAL INTRODUCTION  1  DESCRIPTION AND  6  I.  .RESULTS OF PRESENT RESEARCH  P r e l i m i n a r y I n v e s t i g a t i o n of M e t h y l a t i o n R e a c t i o n s .  6  II.  Large S c a l e M e t h y l a t i o n s and Separations  „...<,  11  III.  C o n c l u s i o n s and T h e o r e t i c a l I m p l i c a t i o n s  . „ . . .  1$  EXPERIMENTAL ,1.. II. HI.  P r e p a r a t i o n of D i e t h y l Mercaptals M e t h y l a t i o n of Mercaptals  . . . . . . . . . .  i n Methyl Iodide  19  . . . .  19  Chromatographic I n v e s t i g a t i o n of the R e a c t i o n Products  'XV.  19  „  „  20  I n v e s t i g a t i o n of the E f f e c t of I n d i v i d u a l c?  Reagents V. VI. VII. VIII.  .  H y d r o l y s i s of the R e a c t i o n Products  Chromatographic I n v e s t i g a t i o n of the  .  22  . » .  23  Methylations 23  . . . . . . . . . . . . . . .  23  . . . . . . . . . . . . .  Large Scale M e t h y l a t i o n of D-Mannose D i e t h y l . . . . . . . . . . . . . .  27  . .  Periodate O x i d a t i o n of Mannose Monomethyl A Fraction  XII.  22  Large S c a l e M e t h y l a t i o n of D-Glucose D i e t h y l  Mercaptal XI.  . ....<>. .  M e t h y l a t i o n of Mercaptals. i n T e t r a h y d r o f u r a n  Mercaptal X.  21  Chromatographic I n v e s t i g a t i o n of the H y d r o l y s a t e s  i n Tetrahydrofuran IX.  . . .  . » . . ' . . . . . '  28  Periodate O x i d a t i o n of Mannose Monomethyl B Fraction  . . . .  . . . . . . . . . . . . . . . .  .  29  XIII. XIV.  P r e p a r a t i o n of D e r i v a t i v e s of Monomethyls Large S c a l e M e t h y l a t i o n of L-Arabinose Mercaptal  BIBLIOGRAPHY  . ,  . . . . . .  A. and B . .  Diethyl  . . „ . . . „ 0  . . . . . . .  APPENDICES . . . . . . . . . . . . .  o . . . .  o .  o c . .  c  Tin  TABLES Page Io II.  P h y s i c a l Constants of D i e t h y l Mercaptals . . „ . „' . R e s u l t s of Chromatograms of the Products of M e t h y l a t i o n s In Methyl I o d i d e  III.  . . . . . . . . .  .  22  R e s u l t s of Chromatograms of the Products of Methylations i n Tetrahydrofuran  V.  21  R e s u l t s o f Chromatograms of Hydrolysed Products of M e t h y l a t i o n s i n Methyl Iodide  IVo  19  ..............  23  Result's: of Chromatograms of Hydrolysed .Products of M e t h y l a t i o n s i n Tetrahydr.ofuran  „ „  .  2'5?  VI... ..Glucose F r a c t i o n s Separated on C e l l u l o s e H y d r o c e l l u l o s e (1:1) VII..  Column  . . . . .  .  28  T h e o r e t i c a l .and Obtained R e s u l t s of Period ate O x i d a t i o n of Monomethyl Mannoses  EC.  26.  Mannose F r a c t i o n s Separated on C e l l u l o s e H y d r b c e l l u l d s e (1:1)  VIII o  Column . . . . . . . . . . . .  Arabinose F r a c t i o n s Separated on Whatman No.. 3MM  30  ix APPENDICES Page A.  Diagram of Chromatographed Products, of M e t h y l a t i o n s 35>  i n Methyl. Iodide < > . . < > B.  Diagram of Chromatographed H y d r o l y s a t e s from Methyl-.-* at.ions i n Methyl Iodide  C.  .  .  .  .  -  6  .  . .* . . . . . . . .-  . . »  37  Diagram of Chromatographed H y d r o l y s a t e s from Methyl38  ations. i n T e t r a h y d r o f u r a n E.  36  Diagram of Chromatographed Products of M e t h y l a t i o n s I n Tetrahydrof.uran  D.  . . . . . . > .  Infra-Red S p e c t r a o f D i e t h y l Mercaptals  . . . . . . .  39  1  HISTORICAL INTRODUCTION In l 8 9 l | , F i s c h e r ^  prepared a new s e r i e s of carbo-  hydrate d e r i v a t i v e s , the t h i o a c e t a l s , or as they are more u s u a l l y c a l l e d , the m e r c a p t a l s .  These compounds were formed  by the a d d i t i o n of mereaptans t o c a r b o n y l compounds i n the presence  of a c i d c a t a l y s t s .  An example of t h i s r e a c t i o n i s  shown below. CHO  CH(SC-He)  ,  ,  HCOH  ' H — *  HCOH  +  1  HOCH  + 2C H^SH 2  2 5 .2  1  HOCH  + H 0 2  HCOH  HCOH  HCOH  HCOH  1  1  CH 0H  CH 0H  2  D-glucose  2  e t h y l mereaptan  (aldehyde form)  D-glucose d i e t h y l mercaptal  Though the r e a c t i o n i s by no means p e c u l i a r t o carbohydrate aldehydes i t s widest  and ketones, i t i s i n t h i s f i e l d  t h a t i t has found  application. The mercaptals have i n t e r e s t i n g p r o p e r t i e s  i n that  they are n e c e s s a r i l y a c y c l i c s i n c e they no longer possess a carbonyl function. to bases and mild reactions  F o r the same reason they are q u i t e oxidants and can t h e r e f o r e  as the Purdie  s i l v e r oxide, u n l i k e  be used  stable  i n such  m e t h y l a t i o n w i t h methyl i o d i d e and  the simple sugars.  S i n c e none of t h e i r  2 h y d r o x y l groups are i n v o l v e d i n r i n g formation,, they lend themselves  t o the p r e p a r a t i o n o f p a r t i a l l y s u b s t i t u t e d sugars  whose syntheses would be u n n e c e s s a r i l y complicated from the v a r i o u s c y c l i c  starting  forms.  (12) I t was r e p o r t e d i n 193^ by L i e s e r and Leckzyck that D-glucose methylated  d i e t h y l mercaptal  (I) could be s e l e c t i v e l y  by the use o f methyl i o d i d e and s i l v e r oxide a t  0°C. t o give e x c l u s i v e l y 2M>methy1-D-glucose d i e t h y l merc a p t a l (II) I n  5>2$  w i t h D-glucose  d i b e n z y l mercaptal  yield.  S i m i l a r r e s u l t s were a l s o obtained (III).  The c o r r e s p o n d i n g  2-p_-methyl-D-glucose (IV) could e a s i l y be o b t a i n e d by a c i d h y d r o l y s i s o f the m e r c a p t a l groups.. F o r t h i s reason i t i s the most e a s i l y a c c e s s i b l e glucose methyl e t h e r . CH(SR) CH(SR)  CHO I . HCOCH.  2  i  HCOH  HCOCHL  i  3  i  HOCH HCOH  HOCH + 2CHoI+Ag 0 -* 2AgI+H 0 + « HCOH  HCOH  HCOH  i  2  l  i  2  J  H 0  I  i  CH OH  2  I  R = -C H^  III  R •= -CH C H^  I  HCOH. CH 0H 2  II.  2  2  HOCH I +2RSH HCOH I  CH 0H  2  2  ^  6  Since the method showed promise, o f an easy route t o s p e c i f i c a l l y substituted mercaptals  sugars, they attempted  the same r e a c t i o n with the  of D-galactose, L-arabinose, D-xylose  They s t a t e d t h a t these f a i l e d  and L-rhamnose„  t o r e a c t i n a s i m i l a r way, s i n c e  they were able t o i s o l a t e no p r o d u c t s , and implied t h a t the  3 r e a c t i o n "was appears  p e c u l i a r t o D-glucose  m e r c a p t a l s , although t h e r e  t o be no a p r i o r i reason why  t h i s should be so.  They  d i d not i n v e s t i g a t e f u r t h e r , s i n c e at t h a t time the problem of s e p a r a t i n g the complex mixtures r e s u l t e d was  almost  insuperable.  the r e a c t i o n , a l b e i t an incomplete extended  T h i s was one,  have  unfortunate f o r i f  c o u l d haye been  to other sugars i n g e n e r a l , the u s u a l l e n g t h y and  difficult be  of p r o d u c t s which may  avoided  i n t r o d u c t i o n and removal of b l o c k i n g groups could i n the p r e p a r a t i o n of p a r t i a l l y methylated  derivatives.  The  sugar  l a t t e r have assumed g r e a t importance  i n the.  d e t e r m i n a t i o n of p o l y s a c c h a r i d e structure-. „ However, s i n c e the i n t r o d u c t i o n of p a r t i t i o n (13) chromatography i h I9J4-I by M a r t i n and Synge  .  a valuable  technique i s a v a i l a b l e f o r the s e p a r a t i o n of complex mixtures of carbohydrates  such as might r e s u l t from incomplete  methyl-  ations. Apart from the above p r a c t i c a l s i g n i f i c a n c e , Lieser"? s work has c o n s i d e r a b l e t h e o r e t i c a l i n t e r e s t w i t h r e s p e c t to the study of r e l a t i v e r e a c t i v i t i e s of h y d r o x y l groups i n sugars.  .  T h i s s u b j e c t has been e x t e n s i v e l y reviewed  by  Sugihara.  The problem i s by no. means c l a r i f i e d however, and  (18)  t h i s applies  i n p a r t i c u l a r t o the r e a c t i v i t i e s of the h y d r o x y l groups i n sugar m e r c a p t a l s , upon which r e l a t i v e l y l i t t l e work has been d one. In t h i s l a t t e r r e s p e c t , L i e s e r ^ - ^ the m e t h y l a t i o n of D-glucose  has  shown t h a t i n  d i e t h y l and d i b e n z y l m e r c a p t a l s ,  k the r e a c t i v i t y of the 2-hydroxyl so f a r exceeds i t s methyl e t h e r r e s u l t s e x c l u s i v e l y .  any other t h a t  This i s i n contrast  to the more random nature of m e t h y l a t i o n i n the f r e e or g l y c o s i d e s , but h i s work has. not i n d i c a t e d t h a t  sugars  this  .unusual r e a c t i v i t y i s g e n e r a l l y e x h i b i t e d by m e r c a p t a l s . Further, Z i n n e r h a s  r e c e n t l y shown t h a t i n p a r t i a l  esteri-  f i c a t i p n s of sugar m e r c a p t a l s , the t e r m i n a l or p r i m a r y h y d r o x y l group  i s c o n s i d e r a b l y more r e a c t i v e than the secondary h y d r o x y l s ,  a phenomenon which i s not as markedly  e x h i b i t e d by o t h e r types (7)  of carbohydrates.  In other r e a c t i o n s , such, as t r i t y l a t i o n ,  the mercaptals appear t o f o l l o w the g e n e r a l trends e s t a b l i s h e d f o r c arbohydrate s. A f a c t o r which r e s u l t s i n the m e r c a p t a l h y d r o x y l s e x h i b i t i n g d i f f e r e n t r e l a t i v e r e a c t i v i t i e s compared to the f r e e sugars, or g l y c o s i d e s i s t h e i r a c y c l i c n a t u r e . and c o - w o r k e r s ^  Barker  have shown t h a t f o r the p o l y o l s at l e a s t ,  t h e r e i s a marked tendency f o r the carbon c h a i n to adopt  the  p l a n a r z i g - z a g form, r e s u l t i n g i n s e l e c t i v i t y i n c e r t a i n reactions.  I t i s reasonable t o suppose t h a t the mercaptals  are s i m i l a r i n nature and that the r e s u l t a n t d i f f e r e n c e s i n conformation of t h e i r h y d r o x y l groups compared t o those a l r e a d y established f o r c y c l i c  sugars w i l l a f f e c t t h e i r  reactivities.  F u r t h e r , the p r o x i m i t y of the b u l k y , e a s i l y p o l a r i s a b l e  sul-  phur atoms i s bound to. e x e r t an e f f e c t on the r e a c t i v i t y of the remainder t h a t D-glucose  of the m e r c a p t a l molecule.  Fischer^  has shown  d i e t h y l m e r c a p t a l i s weakly a c i d i c , g i v i n g a  2-sodium s a l t i n aqueous a l k a l i n e  solution.  In view of the above c o n s i d e r a t i o n s , the aims of the present work are as follows.: (1) A r e i n v e s t i g a t i o n of L i e s e r ' s o r i g i n a l work, t o determine, f i r s t l y i f m e t h y l a t i o n i s e x c l u s i v e at the 2 - p o s i t i o n and secondly, i f any r e a c t i o n does occur with, mercaptals than those of D-glucose,  and  other  i f so, t o what e x t e n t .  (2) An i n v e s t i g a t i o n i n t o the g e n e r a l i t y of the reaction. (3) The  i d e n t i f i c a t i o n of the p r i n c i p a l monomethyl  products of the r e a c t i o n to e s t a b l i s h which, are the most h i g h l y r e a c t i v e p o s i t i o n s , i f any such c l e a r l y e x i s t as i n D-glucose m e r c a p t a l s . The e s t a b l i s h m e n t of whether with, an e f f e c t i v e s e p a r a t i o n technique, an incomplete r e a c t i o n such as the. above can be p r o f i t a b l y extended t o the p r e p a r a t i o n of s p e c i f i c methylated  sugars. The  success of the i n v e s t i g a t i o n i n a c h i e v i n g these  aims w i l l depend on the c o m p l e x i t y of the mixtures of r e a c t i o n products obtained and the a d a p t a b i l i t y of the s e p a r a t i o n techniques of p a r t i t i o n chromatography.  6  DESCRIPTION AND Io  RESULTS, OF PRESENT RESEARCH  P r e l i m i n a r y I n v e s t i g a t i o n of M e t h y l a t i o n R e a c t i o n s The d i e t h y l mercaptals of D-glucose, D-mannose,  D - g a l a c t o s e and L-arabinose were methylated on an e x p l o r a t o r y (12) s c a l e by the method of L i e s e r and Leckzyck.  Upon sep-  a r a t i o n of the. p r o d u c t s from excess methyl i o d i d e arid oxide, syrups were obtained<, D-glucose  The  syrup from the r e a c t i o n of  d i e t h y l mercaptal c r y s t a l l i s e d  g i v e a i|6$ y i e l d  of 2-p_-methy 1 -D-glucose  the others f a i l i n g to y i e l d unchanged m e r c a p t a l . were confirmed.  sliver  spontaneously t o d i e t h y l mercaptal,  any c r y s t a l l i n e m a t e r i a l except  Thus i n a g e n e r a l way  Lieser's results  The mother l i q u o r from the above 2-0-methyl-  D-glucose mercaptal and the remaining t h r e e r e a c t i o n mixtures were i n v e s t i g a t e d , by means of paper p a r t i t i o n chromatography. The developed and detected chromatograms gave a s t r i k i n g l y s i m i l a r p a t t e r n of spots, as shown i n Appendix A,  indicating  q u a l i t a t i v e l y t h a t the r e a c t i o n i s more g e n e r a l than had supposed.  been  The presence of a f u r t h e r amount of. 2-p_-methyl-  D-glucose d i e t h y l mercaptal i n the mother l i q u o r i s a l s o i n d i c a t e d , suggesting t h a t i f d e s i r e d , the y i e l d product could be improved  to approach L i e s e r ' a  of t h i s $2.%.  I t can be seen from the chromatograms arid Table I I that the r e a c t i o n i n each case gave p r o d u c t s of two  types.  Those p r o d u c t s w i t h c o n s i d e r a b l y lower r a t e s of t r a v e l than the u n s u b s t i t u t e d mercaptals are presumably  strongly polar  7 compounds and are of unknown c o n s t i t u t i o n .  However, i t i s  c l e a r t h a t they r e s u l t from a m o d i f i c a t i o n of the m e r c a p t a l groups i n some way,  s i n c e r e a c t i o n at the h y d r o x y l groups  would not .be expected to g i v e r i s e to an i n c r e a s e d p o l a r i t y . The mercaptal; groups have not been removed completely, since, these compounds gave no spot f o r a r e d u c i n g sugar w i t h p-anisidine hydrochloride.  I t i s also.apparent t h a t  these  compounds are p r o b a b l y carbohydrate i n nature s i n c e t h e i r Rp v a l u e s v a r y from sugar to. sugar, s u g g e s t i n g t h a t the molec u l e c o n t a i n s p a r t of the o r i g i n a l sugar moiety.  On h y d r o l y s i s  w i t h a c i d , however, they d i d riot regenerate the p a r e n t  sugars.  The most intense- o f these "slow"  by  spots can be produced  r e a c t i n g the mercaptal with methyl i o d i d e alone, which i n d i cates t h a t t h i s major "slow" of methyl  sulphonium  increase i n p o l a r i t y .  iodide.  component may  p o s s i b l y be a type  T h i s would account f o r the  However, any attempt  at p o s t u l a t i n g  s t r u c t u r e s f o r any of these compounds i s h i g h l y s p e c u l a t i v e and i s i n e f f e c t a separate problem.  I t can be s a i d  definitely  from t h e i r r a t e s of t r a v e l , t h e i r d i f f e r e n t c o l o u r r e a c t i o n w i t h Iodine vapour  and t h e i r f a i l u r e t o y i e l d  acid h y d r o l y s i s , t h a t  these compounds are not  and were not I n v e s t i g a t e d f u r t h e r a t t h i s Prom comparison  sugars  on  mercaptals  time.  w i t h known standards, the  "fast"  spots whieh gave a y e l l o w c o l o u r r e a c t i o n w i t h i o d i n e - v a p o u r are o b v i o u s l y mercaptals and methylated m e r c a p t a l s .  Prom the  d i s t r i b u t i o n and i n t e n s i t y of these i t appeared  reaction  had been most e x t e n s i v e i n the case of D-glucose  that  s i n c e no. spot  8 f o r unchanged mercaptal was appeared  detected.  Somewhat l e s s r e a c t i o n  to have occurred i n the case of D - g a l a c t o s e and o n l y  a s m a l l amount i n the cases of the other two Due  mercaptals  0  to the h i g h Rp. v a l u e s of the mercaptals and  sequent low degree  of chromatographic  con-  s e p a r a t i o n , the products  were h y d r o l y s e d and r e i n v e s t i g a t e d by paper chromatography as the f r e e sugars thus produced.. i n Appendix B.  The r e s u l t s , of t h i s are shown  From a comparison  v a l u e s of known compounds ^  w i t h the c h a r a c t e r i s t i c RQ.  I t appears  t h a t the f i r s t row  spots correspond to u n s u b s t i t u t e d sugars, the second monomethyl d e r i v a t i v e s and the remainder stituted  sugars. (Table I I I . )  some monomethylation has apparent disagreement  to t h e i r  to more, h i g h l y sub-  From t h i s i t can be seen t h a t  occurred i n each case, which i s i n  w i t h L i e s e r * s statement  r e a c t i o n f a i l s f o r sugar mercaptals glucose.  of  t h a t the  other than those of  D-  In- the l a t t e r case the r e a c t i o n g i v e s e x c l u s i v e l y  monomethylation and  s i n c e no u n s u b s t i t u t e d D-glucose  was  d e t e c t e d , a l l the o r i g i n a l m e r c a p t a l must hay© r e a c t e d .  This  agrees with the f i n d i n g s above and a l s o e x p l a i n s the absence of a spot of R  x  = 0.9i? i n the g l u c o s e column In Table I I .  In the r e a c t i o n of D-mannose arid L=arabinose a t i o n appears  mercaptals  methyl-  t o have gone to. the monomethyl stage a l s o , but  to a much l e s s e r extent s i n c e l a r g e amounts of the unchanged sugars"were d e t e c t e d .  However, i n the r e a c t i o n of D - g a l a c t o s e  m e r c a p t a l some p o l y m e t h y l a t i o n has  a l s o taken place,.  These  r e s u l t s suggest the reason f o r L i e s e r ' s f a i l u r e to i s o l a t e any c r y s t a l l i n e products except i n the case of D-glucose;  9 i n two i n s t a n c e s the s m a l l amounts of products seem t o be r e s p o n s i b l e and i n the o t h e r , the complexity of the r e a c t i o n mixtur e. Prom the above evidence i t again appeared  t h a t the  s e l e c t i v i t y of the r e a c t i o n , i f not the, e x t e n t , was more g e n e r a l than had been supposed,  at least  D-mannose and L-arabinose were concerned.  as f a r as D-glucose, The evidence from  the D-galactose h y d r o l y s a t e was somewhat i n disagreement. During t h i s p r e l i m i n a r y work i t was observed  that  there were c o n s i d e r a b l e d i f f e r e n c e s In the s o l u b i l i t i e s of the v a r i o u s mercaptals i n methyl i o d i d e .  Under the c o n d i t i o n s  used, i t was found that the extent of m e t h y l a t i o n corresponded approximately t o the degree of s o l u b i l i t y of the m e r c a p t a l being r e a c t e d .  particular  In t h i s r e s p e c t D-glucose d i e t h y 1  m e r c a p t a l was found to be most s o l u b l e and i t s unusual reactivity  appeared  i n p a r t due t o the f o r t u i t o u s c h o i c e of  methyl i o d i d e as r e a c t i o n s o l v e n t .  Large amounts of D-mannose  and L-arabinose mercaptals were found u n d i s s o l v e d at the end of the r e a c t i o n and these mercaptals appeared r e a c t e d t o the l e a s t  t o have  extent.  In order to e l i m i n a t e t h i s  s o l u b i l i t y effect  i t was  decided t o i n c o r p o r a t e an i n e r t r e a c t i o n s o l v e n t i n which a l l f o u r mercaptals had comparable s o l u b i l i t i e s and compare the r e a c t i o n of each again on a more e q u a l b a s i s .  The most  able of the common organic s o l v e n t s which are i n e r t t o m e t h y l a t i o n was found t o be t e t r a h y d r o f u r a n . S i n c e the  suit-  10  presence of a l a r g e amount of i n e r t s o l v e n t was found t o quench the r e a c t i o n almost e n t i r e l y , i n c r e a s e d amounts of methyl i o d i d e and s i l v e r oxide were used.  In o r d e r t o d e t e r -  mine i f changing the o r i g i n a l r e a c t i o n temperature  of 0°G„ had  any c r i t i c a l e f f e c t on the n a t u r e of the p r o d u c t s , three p a r a l l e l r e a c t i o n s were c a r r i e d out on each m e r c a p t a l a t 3 ° , 22°, and £0°C. The  syrupy products were separated from the r e a c t i o n ,  mixtures as b e f o r e , however i n t h i s case none o f them crystallised  spontaneously.  They were a g a i n i n v e s t i g a t e d  by paper chromatography, the r e s u l t s b e i n g shown i n Appendix 0 and T a b l e IV.  The g e n e r a l i t y of the r e a c t i o n was again  I n d i c a t e d from the s i m i l a r i t y o f the p a t t e r n of spots obtainedo  The unusual r e a c t i v i t y of D-glucose  mercaptal was not now so markedly  diethyl  apparent s i n c e a spot was  obtained f o r unchanged m e r c a p t a l at a l l t h r e e  temperatures.  The p r o d u c t s were h y d r o l y s e d and re chromat ographe d as b e f o r e , the r e s u l t s o f t h i s being shown i n Appendix Some monomethylation polymethy1at1on  D and Table V.  has again occurred i n each case and a l s o  which was p r e v i o u s l y absent i n t h r e e of the  r e a c t i o n s when c a r r i e d out i n methyl i o d i d e . m e t h y l a t i o n appeared  more comparable  The extent of  i n each case-.  i n g c o n c l u s i o n s were drawn from these results„  The f o l l o w -  F i r s t l y , the  p e c u l i a r s e l e c t i v i t y of the r e a c t i o n of D-glucose  diethyl  mercaptal was no l o n g e r apparent when c a r r i e d out i n t e t r a hydrofuran. this solvent.  Secondly, the r e a c t i o n appeared more g e n e r a l i n T h i r d l y , the e f f e c t of v a r y i n g the r e a c t i o n  11 temperature IIo  d i d not seem to be of c r i t i c a l  Large Scale. M e t h y l a t i o n s and  importance.  Separations  In the l i g h t of the above evidence i t was  decided  to repeat the m e t h y l a t i o n s on a l a r g e r s c a l e t o o b t a i n workable q u a n t i t i e s of the products  and  attempt  a s e p a r a t i o n and  i s o l a t i o n of the products as q u a n t i t a t i v e l y as p o s s i b l e . Although complete r e c o v e r y of the p r o d u c t s i s not f e a s i b l e due  to chromatographic  l o s s e s , the r e l a t i v e y i e l d s which Can  be obtained are of value i n e s t a b l i s h i n g which are the major products.  I t was  f u r t h e r decided to i n v e s t i g a t e the mono-  methyl f r a c t i o n s most thoroughly to determine  i f preferential  m e t h y l a t i o n had occurred at the 2 - p o s i t i o n . A l a r g e s c a l e m e t h y l a t i o n of D-glucose mercaptal was  diethyl  c a r r i e d out i n t e t r a h y d r o f uran at 22°C.  decided to remove the u n d e s i r e d l a t e r contaminate  I t was  "slow" components which might  the other p r o d u c t s .  The  syrupy r e a c t i o n  products were t h e r e f o r e subjected to a crude p r e l i m i n a r y separation  b  y  colu»n c h , o a t o r a p h  non-mereaptai f r a c t i o n .  m  g  ( i 9 ) y  Into a e r c a p t a l and m  The former was h y d r o l y s e d as before  and the mixture of f r e e sugars separated by a more r e f i n e d a p p l i c a t i o n of column chromatography„  The f r a c t i o n s  collected  were i n v e s t i g a t e d s y s t e m a t i c a l l y by paper chromatography and p o l a r i m e t r y to l o c a t e i n d i v i d u a l sugars.  The r e s u l t s g i v e n i n  Table VI show that t h e r e are s i x d i f f e r e n t methyl glucoses i n a d d i t i o n to. some unchanged sugar. contents were, obtained to determine  The Rp v a l u e s and methoxyl the degree of m e t h y l a t i o n  12 In each of the p r o d u c t s . The monomethyl f r a c t i o n was only by i t s chromatographic r o t a t i o n throughout  p u r i t y and constancy of o p t i c a l  the f r a c t i o n .  s i n g l e product of the r e a c t i o n . spontaneously  and f a i l e d  shown to be one. component  I t i s thus the This f r a c t i o n  largest  crystallised  to depress the m e l t i n g p o i n t of an  a u t h e n t i c sample of 2>0-methyl-D-glucose on admixture I t was  f u r t h e r c h a r a c t e r i s e d as 2 - p_-me thy 1 -D - glue o s e  i t s p-toluidide  through  derivative.  The polymethyi f r a c t i o n s were not f u r t h e r gated o  with'it.  investi-  The y i e l d s of the o r i g i n a l products of m e t h y l a t i o n  were estimated  and  are g i v e n below.  TFnreacted D-glucose  d i e t h y l mercaptal  2.02$  Monomethyl  "  "  "  8.36$  Dimethyl  "  "  "  10.$$%  Trimethyl  "  "  "  $.19%  I t should again be emphasized t h a t these do not take account mechanical  into  l o s s e s and are o n l y of v a l u e i n showing the  g e n e r a l extent of m e t h y l a t i o n . The  important  r e s u l t Is t h a t although the o n l y mono-  methyl d e r i v a t i v e r e s u l t i n g from the m e t h y l a t i o n i s the 2-0-methyl, the r e a c t i o n i n t h i s s o l v e n t i s no l o n g e r so s e l e c t i v e as to y i e l d  this exclusively.  The  a d d i t i o n of a  s o l v e n t seems t o favour p o l y m e t h y l a t i o n , p o s s i b l y due i n c r e a s e d s o l u b i l i t y of the r e a c t a n t s . of glucose mercaptals  Hence the  i n L i e s e r ' s work appears  t o the  singularity  to be a  13 consequence of the r e a c t i o n s o l v e n t used. The above m e t h y l a t i o n and s e p a r a t i o n of products was repeated on D-mannose d i e t h y l m e r c a p t a l .  The r e s u l t s  are g i v e n i n Table V I I , showing t h a t there are e i g h t d i s t i n c t methyl mannoses i n a d d i t i o n t o some unchanged D-mannose. degree o f m e t h y l a t i o n i n each product was determined  The  as b e f o r e .  Of the f o u r monomethyl mannoses, two were p r e s e n t i n n e g l i g i b l e amounts and were considered to be r e l a t i v e l y unimportant.  The two predominant monomethyl sugars were sub-  jected to periodate o x i d a t i o n studies.  The r e s u l t s of t h i s ,  g i v e n i n Table V I I I , i n d i c a t e d t h a t the l a r g e r was 6-0-methyland the l e s s e r 5>-0-methyl-D-mannose.  These were f u r t h e r  c h a r a c t e r i s e d through t h e i r phenylosazones„ The y i e l d s of the o r i g i n a l products were estimated as b e f o r e and are g i v e n below. Unreaeted  0*$3%  D-mannose d i e t h y l m e r c a p t a l  Monomethyl  "  "  "  12„07$  Dimethyl  "  "  "  3.88$  Trimethyl  "  "  "  21.i|£#  The r e s u l t s i n t h i s case show t h a t r e a c t i o n does hot p r e dominate at the 2 - p o s i t i o n n o r at any one p o s i t i o n .  Never-  t h e l e s s the primary h y d r o x y l i s a p p a r e n t l y most r e a c t i v e , with the ^ - p o s i t i o n a l s o b e i n g h i g h l y .reactive. t o t a l y i e l d of methylated  p r o d u c t s i s now more comparable w i t h  that obtained from D-glucose Iodide was used  F u r t h e r , the  d i e t h y l mercaptal than when methyl  as r e a c t i o n s o l v e n t .  However, the monomethyl  d e r i v a t i v e s are not the l a r g e s t products o f the r e a c t i o n ,  s i n c e m e t h y l a t i o n has a p p a r e n t l y proceeded trimethy1  l a r g e l y t o the  stage. A l a r g e s c a l e m e t h y l a t i o n and p r e l i m i n a r y crude  f r a c t i o n a t i o n was e x a c t l y as b e f o r e . was  carried  out on L-arabinose d i e t h y l  mercaptal  The f i n a l r e f i n e d ' s e p a r a t i o n , however,  e f f e c t e d by paper chromatography, f o l l o w e d by r e c o v e r y of  the i n d i v i d u a l sugars from the developed of the a p p r o p r i a t e zones.  chromatograms by  The r e s u l t s are g i v e n i n Table  elution IX,  showing that there are seven d i s t i n c t methyl arabinoses p r e sent but no unchanged L - a r a b i n o s e . products were estimated  The y i e l d s of the  as b e f o r e and are g i v e n below.  Monomethyl L-arabinose d i e t h y l m e r c a p t a l Dimethyl The  original  "  11  "  2.1$ .26.8$  r e s u l t s do not show t h a t m e t h y l a t i o n predominates at  any one p o s i t i o n .  Apart from the l e s s s p e c i f i c n a t u r e of  m e t h y l a t i o n , r e a c t i o n appears  t o have gone l a r g e l y t o the  dimethyl stage, w i t h three of the f o u r p o s s i b l e monomethyl arabinoses b e i n g p r e s e n t o n l y i n n e g l i g i b l e amounts. total yield  of methylated  w i t h t h a t from D-glucose was  p r o d u c t s Is now  The  more comparable  m e r c a p t a l than when methyl i o d i d e  used as r e a c t i o n s o l v e n t . Prom the d i v e r s i t y of spots obtained i n the p r e -  l i m i n a r y i n v e s t i g a t i o n of D-galactose d i e t h y l m e r c a p t a l i t d i d not appear that any p a r t i c u l a r s e l e c t i v i t y of r e a c t i o n was  exhibited.  Indeed, an e x p l o r a t o r y s e p a r a t i o n of the  products showed that the monomethyl f r a c t i o n was  not  homogeneous, i n d i c a t i n g t h a t r e a c t i o n d i d not predominate at any  one p o s i t i o n .  to be  I t was  obtained d i d not  felt  t h a t the value of the r e s u l t s  j u s t i f y a r e p e t i t i o n of the  above l a r g e  s c a l e work on D-galactose d i e t h y l m e r c a p t a l at t h i s time. Illo  C o n c l u s i o n s and  Theoretical  Implications  Gf the mercaptals i n v e s t i g a t e d both by L i e s e r and. i n the p r e s e n t work, only the D-glucose d e r i v a t i v e s e x h i b i t unusual r e a c t i v i t y of the 2-hydroxyl group. c o n d i t i o n s m e t h y l a t i o n has t h i s p o s i t i o n and i n e r t solvent  clear.  1  been shown to occur e x c l u s i v e l y at  although r e a c t i o n i s l e s s s e l e c t i v e when an  i s used, the 2-_0-methyl i s the  ether formed. not  Under L i e s e r s  s o l e monomethyl  The r e a s o n s f o r t h i s p e c u l i a r r e a c t i v i t y  L i e s e r ( l ^ ) s t a t e d that the. r e a c t i v i t y of  2-hydroxyl i s p a r t i c u l a r l y i n c r e a s e d  by the  the  neighbouring  m e r c a p t a l groups, presumably by an e l e c t r o n i c e f f e c t . t h i s Is true-, i t i s d i f f i c u l t  to see  why  h y d r o x y l groups.  That there  If  t h i s e f f e c t i s not  e q u a l l y p r e s e n t i n other mercaptals which are those of D-glucose except f o r the  are  i d e n t i c a l with:  c o n f i g u r a t i o n of t h e i r  i s such an e f f e c t appears to  be  e s t a b l i s h e d by  the a c i d i t y of the 2-hydroxyl as demonstrated  by F i s c h e r ^ ,  and  g l u c o s e s do not i n methylation.  show t h i s p e c u l i a r r e a c t i v i t y of the  2-hydroxyl.  2-position  I t Is d o u b t f u l , however, t h a t t h i s e f f e c t i s  s o l e l y responsible the  a l s o by the f a c t t h a t non-mercaptalated  f o r producing the unusual r e a c t i v i t y  of  16 The p o s s i b i l i t y of a p u r e l y s t e r i c e f f e c t o p e r a t i n g i n c o n j u n c t i o n w i t h the above e l e c t r o n i c e f f e c t was c o n s i d ered.  I t i s r e a s o n a b l e to assume t h a t the p r o x i m i t y of the  mercaptal groups c o n f e r s p o t e n t i a l r e a c t i v i t y on the 2 - p o s i t i o n i n a l l the sugar mercaptals„  However, i f the a v a i l a b i l i t y of  t h i s p o s i t i o n to a t t a c k were reduced due the b u l k y mercaptal groups  to b l o c k i n g by  either  or the r e s t of the molecule,  this  p o t e n t i a l r e a c t i v i t y would be diminished arid perhaps no l o n g e r apparent.  A study of models of the f o u r m e r c a p t a l molecules  was made.  Various s p a t i a l arrangements of the groups were  considered In an attempt to minimize non-bonded but In no case d i d these r e v e a l any pronounced  interactions, differences  between the v a r i o u s mercaptals In the a v a i l a b i l i t y of the 2-position.  Hence i t appears t h a t t h i s s t e r i c e f f e c t i s not  r e s p o n s i b l e f o r the marked d i f f e r e n c e between g l u c o s e and  the  other m e r c a p t a l s . A c o n s i d e r a t i o n of the conformation of the h y d r o x y l groups 'in the p l a n a r z i g - z a g form, e s t a b l i s h e d by Barker^ f o r the p o l y o l s , suggested the p o s s i b i l i t y of d i f f e r e n c e s i n hydrogen-bonding  b e i n g r e s p o n s i b l e f o r the s i n g u l a r i t y of  glucose m e r c a p t a l s .  The g r e a t e r the extent of  hydrogen-  bonding, the l e s s r e a c t i v i t y would be expected from an a l c o hol i n a nucleOphilic  s u b s t i t u t i o n r e a c t i o n such as. methyl-  ation.  s p e c t r a of the f o u r mercaptals  The  infra-red  (Appendix E) show marked d i f f e r e n c e s i n the p o s i t i o n of the h y d r o x y l peak.  The peak f o r glucose m e r c a p t a l at 339^  cm"-*-  17  i s shifted  the f u r t h e s t towards the h i g h frequency r e g i o n o f  the spectrum i n d i c a t i n g l e a s t hydrogen-bonding, w i t h p r o g r e s s i v e l y more for' g a l a c t o s e , mannose and arabinose  mercaptals  as i n d i c a t e d by the p o s i t i o n s ' of t h e i r peaks at 3320, 3280 and 3275> cm  respectivelyo  Thus the g r e a t e r freedom, of the  h y d r o x y l groups i n c o o p e r a t i o n w i t h the e f f e c t o f the n e i g h b o u r i n g m e r c a p t a l groups suggests unusual behaviour  an e x p l a n a t i o n f o r the  of glucose mercaptal  compared t o the other  mercaptals„ A c o m p l i c a t i o n i s i n t r o d u c e d when t e t r a h y d r o f u r a n i s the r e a c t i o n s o l v e n t .  S i n c e i t i s capable  of solvent-  s o l u t e hydrogen bonding whereas methyl i o d i d e i s n o t , i t might be expected  t h a t d i f f e r e n c e s i n the i n t e r - and i n t r a m o l e c u l a r  hydrogen-bonding of the v a r i o u s mercaptals smoothed out i n the presence s o l v e n t molecules.  o f a l a r g e number of bonding  This" would r e s u l t i n more s i m i l a r  v i t y of the 2-hydroxyls. does indeed reduce  would tend t o be  The presence  of tetrahydrofuran  the marked r e a c t i v i t y of the 2-hydroxyl  over the other h y d r o x y l s i n g l u c o s e m e r c a p t a l by the occurrence  reacti-  as evidenced  of p o l y m e t h y l a t i o n , but a p p a r e n t l y does n o t  s i g n i f i c a n t l y i n c r e a s e the r e a c t i v i t y of t h i s p o s i t i o n i n other  mercaptals. The  e f f e c t of the d i e l e c t r i c  constant o f the s o l v e n t  used has b e e n c o n s i d e r e d , but s i n c e a l l the r e a c t i o n s i n v o l v e methyl i o d i d e they p r o b a b l y take p l a c e by the same mechanism. Hence changes i n the d i e l e c t r i c constant o f the medium would  18 not be expected  t o a f f e c t p a r t i c u l a r h y d r o x y l groups.  The complexity of the v a r i o u s e l e c t r o n i c , , e l e c t r o s t a t i c and c o n f o r m a t i o n a l e f f e c t s s i m u l t a n e o u s l y o p e r a t i v e makes any complete e x p l a n a t i o n of the p e c u l i a r i t y of glucose: mercaptals i m p o s s i b l e without r e c o u r s e t o f u r t h e r i n v e s t i g a t i o n . study of the r e l a t i v e importance  A  of these f a c t o r s seems d e s i r -  able . A knowledge of these f a c t o r s would a l s o be of value i n extending the r e a c t i o n t o the p r e p a r a t i o n of s p e c i f i c a l l y s u b s t i t u t e d d e r i v a t i v e s of sugars other "than. D-glucose.  There  Is promise o f t h i s i n the r e s u l t s from the m e t h y l a t i o n of D-mannose m e r c a p t a l .  A d j u s t i n g the r e a c t i o n c o n d i t i o n s  should lead t o more p r a c t i c a l y i e l d s of the £-j3-methyl and 6r0-methyl ethers.  Although the r e s u l t s from the m e t h y l a t i o n s  of D-galactose and L-arabinose mercaptals do not show any promise under the c o n d i t i o n s used, p a r t i a l m e t h y l a t i o n s of mercaptals of these and o t h e r sugars not y e t i n v e s t i g a t e d may be of p r e p a r a t i v e and t h e o r e t i c a l value i f suitable, cond i t i o n s can be  determined.  19  EXPERIMENTAL A l l m e l t i n g p o i n t s were taken .by means of a L e i t z e l e c t r i c a l l y heated m e l t i n g p o i n t b l o c k and are c o r r e c t e d . A l l evaporations were done i n vacuo a t l|.0 C. o  Methoxyl  analyses were c a r r i e d out by the method of Viebock and Schwappach as d e s c r i b e d by C l a r k . (2). I.  P r e p a r a t i o n of D i e t h y l Mercaptals The f o l l o w i n g mercaptals were prepared by the  method of F i s c h e r ^  , and t h e i r p h y s i c a l constants are  g i v e n i n Table I . , Table I P h y s i c a l Constants  of D i e t h y l Mercaptals PO  Mercaptal.  M.P.  PO  [«]^(lf).  Lit.M P. 0  D-glucose  128-129°C . 1 2 7 - 1 2 8 ° C . (ij.). - 2 7 ° ( H 0 ) *  D-mannose  133-13i|- C.  2  0  13i|- Co(10)  o  ll).0-llj.2 C. (i*.)  L-arabinose 1 2 l | . - 1 2 5 C  o  1 2 ^ - 1 2 6 ° C . (Ij.)  0  0  *  1 1  -29„8°(H20)*  0°(Pyridine) -  0  D-galactose 3 i j . 0 - 1 ^ 2 C o  Yield  -9°(H 0) 2  $3%  -10°(H 0)  Q\%  2  60$  Pyridine) -  o R o t a t i o n of this, compound was measured at 5>0 C „ •' M e t h y l a t i o n of Mercaptals i n Methyl, Iodide D-glucose  d i e t h y l m e r c a p t a l was methylated  method of L i e s e r arid L e c k z y c k ^ . was shaken with s i l v e r oxide  The mercaptal  by the  (0v9Ji  (1.5> gm„) and methyl i o d i d e  gm.)  (10 ml.)  f o r 21 hours at 0°C. under anhydrous c o n d i t i o n s .  F i n a l l y , the mixture .was  allowed to a t t a i n room  (one hour) and f i l t e r e d .  The  r e s i d u e was  temperature  e x t r a c t e d succes-  s i v e l y w i t h b o i l i n g c h l o r o f o r m , acetone .and methanol.. filtrate  and e x t r a c t s were combined and evaporated  which was  taken up i n a s m a l l amount of methanol.  t h i s s o l u t i o n deposited c r y s t a l s glucose d i e t h y l mercaptal, m.p.  (0.1|6 gm.)  to a syrup On s t a n d i n g  of 2-0-methy 1 -D-  lj?i|.-li?£C. Li,t.m.p„ 'l££-15>6 C. 0  (12) A n a l : Gale, f o r C ^ H ^ O ^ : -OCH^ -OCH3 = 10.99.  The  0  10.37$°  Found:  Y i e l d Ij.6$.  The d i e t h y l mercaptals  of D-mannose, D-galactose  and  L-arabinose were a l s o methylated by the above procedure,  but  the syrups obtained f a i l e d  to y i e l d  any c r y s t a l l i n e  I I I . Chromatographic. I n v e s t i g a t i o n of the R e a c t i o n  product. Products  Chromatograms of the f o u r r e a c t i o n products above were run on Whatman No.  1 paper u s i n g  (14.0:10:^0) as developer.  n-butanol-e.thanol-water  D e t e c t i o n of the chromatograms  w i t h i o d i n e vapour (5>) showed the p a t t e r n of spots represented i n Appendix A.  Table: I I g i v e s the R  x  v a l u e s and d e s c r i p t i o n s  of the spots produced. F u r t h e r d u p l i c a t e chromatograms were detected w i t h p - a n i s i d i n e h y d r o c h l o r i d e but f a i l e d reducing  sugars.  to y i e l d  any spots f o r  21 Table I I R e s u l t s of Chromat ograras of the Products of M e t h y l a t i o n s i n Methyl Iodide D-Glueose mercaptal  D-Mannose mercaptal  Ry? D e s c r i p t i o n R f  0.13 0.21  OF  0.36  x  OF  0.10 0.18  01  0.36  Description R  OF  01  -  -  0.924-  YI  I.07  YF  TI  x  0.13 0.21  OF  1.00  D-Galactose mercaptal  L-Arabinose mercaptal  Description R  Description  x  OF  OF  0.13 0.21  O.ifO  01  O.I4.O  01.  O.lj.7  OF  0.i|6  OF  YF  o.?5**  YI  YI  1.0£  YF  OF  1.03  OF  "'^R- i s based on the a r b i t r a r y standard 2 - 0_-me thy 1 -D - glue o s e d i e t h y l m e r c a p t a l whose r a t e i s s e t equal t o 1.00. '""These v a l u e s correspond t o standards o f t he u n s u b s t i t u t e d mercaptalSi Key;  IV.  0 = Orange.  Y = Yelloxv  I = Intense  F = Faint.  I n v e s t i g a t i o n of the E f f e c t of, I n d i v i d u a l Reagents Two samples o f D-glucose  d i e t h y l mercaptal  (10  mgm.)  were d i s s o l v e d i n carbon tetrachloride•(5> m l i ) and shaken f o r 21 hours at 0°C. w i t h methyl i o d i d e and s i l v e r oxide r e s p e c t i v e l y . A f t e r f i l t e r i n g , the s o l u t i o n s were chromatographed w i t h standards and detected as b e f o r e .  The r e s u l t s are g i v e n below.  A. Me thy1. io.dide .treated mereaptal.: Three  0.35*  (Intense) and  O.9I4.  spots o f R  (unchanged m e r c a p t a l ) .  x  =  0.21,  22 B. S i l v e r oxide t r e a t e d m e r c a p t a l :  One  spot of R  =  x  0.95>  (unchanged m e r c a p t a l ) . V. H y d r o l y s i s of the R e a c t i o n  Products 20$  The r e a c t i o n products from I I were d i s s o l v e d i n aqueous ethanol c o n t a i n i n g was heated  hydrogen c h l o r i d e .  The  solution  to r e f l u x , a stream Of n i t r o g e n b e i n g bubbled  continuously„•  through  When chromatography of the s o l u t i o n s f a i l e d  d e t e c t any unchanged mercaptals  to  (jj>~6 h o u r s ) , they were passed  through a column of D u o l i t e A-l}. anion exchange r e s i n and  con-  c e n t r a t e d by evaporation,, VI. Chromatographic I n v e s t i g a t i o n of the H y d r o l y s a t e s The: above hydrolysates, were chromatographed as i n I I I and detected w i t h p - a n i s l d l n e h y d r o c h l o r i d e , the r e s u l t s being shown i n Table I I I . Table I I I R e s u l t s of Chromatograms,of Hydrolysed M e t h y l a t i o n s i n Methyl Glucose Hydrolysate  0;23  I  Products  of  Iodide  Mannose Hydrolysate  .Galactose .Hydrolysate  0.11  I  0.08  F  0.12  0.28  F  0.22  F  0.3k  0.39  P  0.72  P  0.86  Arabinose Hydrolysate I F  F (The values g i v e n are RQ. v a l u e s based on 2 , 3 , 4 , 6 - t e t r a - O - m e t h y l D-glucose = 1.00) ""  23 V I I . M e t h y l a t i o n of Mercaptals The mercaptal  i n Tetrahydrofuran  ( 0 . 3 gm.)  f r e e t e t r a h y d r o f u r a n (20 m l . ) .  was d i s s o l v e d i n d r y peroxide A f t e r s i l v e r oxide  (1 gm.)  and  methyl i o d i d e (10 ml.) were added, the whole was shaken v i g o r o u s l y f o r 22 hours. ried  out on each mercaptal  Three p a r a l l e l experiments were c a r at 3°,  22°  and j?Q°C.  The products  were then e x t r a c t e d as b e f o r e , no c r y s t a l l i n e materials, being obtained. V I I I . .. Chromatographic I n v e s t i g a t i o n ..of the M e t h y l a t i o n s i n . Tetrahydrofuran Chromatograms of the syrupy products from the above were run as b e f o r e and detected w i t h iodine, vapour. The mixtures were then h y d r o l y s e d ethanol-water chloride.  as, i n V., rechromatographed i n n-butanol-  (1|0:10:50) and detected with, p - a n i s i d i n e hydro-  The r e s u l t s are presented  i n Tables, IV and V r e s -  pectively. IX. ' Large S c a l e Methylation. of D-Glucose D i e t h y l M e r c a p t a l S i l v e r oxide  (6.7  gm.)  and methyl Iodide  added t o a s o l u t i o n of D-glucose d i e t h y l mercaptal in purified  t e t r a h y d r o f u r a n (100  ml.).  (67  ml.) were  (2.0  gm.)  The v e s s e l was f l u s h e d  w i t h n i t r o g e n , sealed and shaken a t room temperature f o r 22 hours..  (.2.07  The products were e x t r a c t e d as i n I I , an amber gm.)  being  obtained.  syrup  Table I V  .  R e s u l t s of Chromatograms of the Products of Methylations i n Tetrahydrofuran* D-Glucose  D-Mannose  22°  gQ°  0.11  0,10  0.12  0.10  0.10  0.10  0.12  0.13  0.12  0.12  0.13  O.llj.  0.20 0.20 0.20  0.17  0.18  0.20  0.21  0.21  0.22  0.21  0.21  0.22  0.36  0.36  0.36  0.36  O.36  0.39  0.39  O.lj.0  0.38  O.ifO  O.la  0.9$  0o9$ 0 . 9 ^  IcOO  loOO  1.00  22°  ,3,.o .= 22°  £0°  0.9^ 0.96 0.95  0.96 0.96  1.01  IcOl  1.00  The v a l u e s g i v e n are R d i e t h y l m e r c a p t a l = 1.00  to to  £0°  L-Arabinose  3°  0.36  3°  D-Galactose  1.01  x  1.02  v a l u e s based  3°  0.96 1.01  £0.°  22P..  -** 1.02  0.97  1.03  1.03  on 2-0-methy1-D-glueose "~  The absence of a spot f o r unreacted m e r c a p t a l c o r r e s p o n d i n g the spots f o r L-arabinose produced on h y d r o l y s i s may be due the g r e a t e r s e n s i t i v i t y of the p - a n i s i d i n e .  Paper chromatography of the above syrup u s i n g methyl e t h y l ketone-water  azeotrope as developer g a v e . e s s e n t i a l l y the  same r e s u l t s as shown i n the f i r s t column of Table I V . aliquot  (1.96. gm.)  diam. x ij.0 cm.  was p l a c e d on a c e l l u l o s e column (2.8  at  cm.  length) and developed w i t h the same s o l v e n t .  F r a c t i o n s were c o l l e c t e d (Two  An  at one hour' i n t e r v a l s , f o r e i g h t  column f r o n t times)  Two  f r a c t i o n s were then  collected  two hour i n t e r v a l s and the r e m a i n i n g m a t e r i a l was  from the column by d e v e l o p i n g f o r a f u r t h e r 80 h o u r s , times) without any attempt grams of the f i r s t  at fractionation'.  hours.  removed (20 f r o n t  Paper chromato-  e i g h t f r a c t i o n s developed with, methyl  ethyl  2$ Table ,V R e s u l t s of Chromatograms of the Hydrolysed  Products  of  Methylations i n Tetrahydrofuran D-Glucose Hydrolysate ,  3°  D-Mannose Hydroylsate  D-Galactose. Hydrolysate  22°  ,gQ°  0.09 0.09  0.1.1  0.12 0.13 0.13  0.07 0.08 0.08  0.13  0.23 0.23  0.26  0.2£ 0.26 0.28  0.18, 0.20 0.23  0.32 0.32 Ov34  O.I4.O O.lj.2 0.J+3  0.1+2 0.4S 0.4s  0.36 0.38 0.40  0.1)4 0-k% 0.I4.3  3° -22°  g0°  3,o  22°-  L-Arablnose Hydrolysate $0°  :  0.46 0.47 0.£2 The values g i v e n are R^ D-glucose  -  values based  on  30.  $0°.  22°  0.12  0.12  o.$o  o.$o 0.49  0.62  0.6^  0.6$  2,3 ,l)-,6 -tetra-Q-methy1-  1.00  ketone-water and detected w i t h i o d i n e vapour i n d i c a t e d good s e p a r a t i o n had been achieved.  fairly  F r a c t i o n s 2-$ were found  to  c o n t a i n a l l the: mercaptalated products w i t h s l i g h t t r a c e s  of  undesired i m p u r i t y .  These were combined  designated as m e r c a p t a l f r a c t i o n .  (0.879 gm.)  and  The h i g h e r f r a c t i o n s " were  discarded. The m e r c a p t a l f r a c t i o n was h y d r o l y s e d as b e f o r e , passed through a D u o l l t e A-I4. column and the e l u a t e concentrated to a syrup  (0„42^ gm.)  by e v a p o r a t i o n .  Two  chromatograms of the  l a t t e r were run i n methyl e t h y l ketonerwater  and detected w i t h  i o d i n e vapour and p - a n i s i d i n e h y d r o c h l o r i d e r e s p e c t i v e l y . first  The  chromatogram showed no spots corresponding t o glucose  mercaptals  i n d i c a t i n g h y d r o l y s i s , was  complete.  The; second  26 showed f o u r  spots o f Rp'a OoOlij.,  i n g t o the c h a r a c t e r i s t i c R and  t r i m e t h y l glucoses An  aliquot  F  0.06, 0.21 (3)  ranges  and 0.1+7 correspond-  of g l u c o s e , mono-, d i -  respectively.  (O.I4.O6 gm.) of the above, h y d r o l y s a t e i n the  minimum amount of methyl e t h y l ketone was placed (2.8  x  1+2 cm.) of c e l l u l o s e - h y d r o c e l l u l o s e  w i t h methyl e t h y l ketone-water azeotrope.  on a column  (1:1) and developed Fractions  were c o l -  l e c t e d at 30 minute i n t e r v a l s a t a f l o w r a t e of I4.O ml. p e r hour. A f t e r 300 f r a c t i o n s had been .collected no f u r t h e r carbohydrate: material  could  be detected i n the e l u a t e by a p p l i c a t i o n of the  M o l i s c h t e s t and f r a c t i o n a t i o n was t e r m i n a t e d . were i n v e s t i g a t e d  The f r a c t i o n s  s y s t e m a t i c a l l y by paper chromatography, mea-  surement of o p t i c a l r o t a t i o n and d e t e r m i n a t i o n of methoxyl v a l u e to o b t a i n  the f o l l o w i n g  classification. Table V I .  Glucose F r a c t i o n s , Separated on C e l l u l o s e Hydrocellulose C l a s s i f i c a t i o n Tube .No. Hexose Monomethyl D.ijnethyl A Dimethyl B Dimethyl C Trimethyl A Trimethyl B  238-270 l69r235 $l~7k  86-108 30-^0  28-29  12-19  Wt (mgm.) 0  .23  lOij. $0  1+7  1+2 11 63  (1:l)  Column [oc]  2 0  +ij.8°(H20)  +59°(H"20)  R ^ * % OCR*.  0.017  0 0> + 8'2o.( Acetone) 0.28 +32°(Acetone) 0.18 +6l°(Me0H) 0.1+7 +91°(Me0H) 0.50 +20°(H20) 0.80 o  l£.7 26.£  2J4..8 27.3  36.6  36.7  ",R values determined i n methyl e t h y l ketone-water azeotrope. F """^Calculated methoxyl values, f o r mono,-, d i - and t r i m e t h y l hexoses r e s p e c t i v e l y a r e 16..0, 29.8 and 1+1.9$.  27 A l l the above f r a c t i o n s were found g r a p h i c a l l y pure except and  B.  to be  chromato-  f o r some overlap between Dimethyls A  The monomethyl f r a c t i o n a l s o showed constancy  of  optical  r o t a t i o n throughout the f r a c t i o n and y i e l d e d a c r y s t a l l i n e duct m e l t i n g a t l £ 3 - l £ 7 ° C . of  pro-  Admixture w i t h an a u t h e n t i c sample  2-0-methy 1-D-glucose gave a m e l t i n g p o i n t of  l$l±-l$Q C. 0  (17) The p - T o l u i d i d e was  prepared  nljlj.-146°C. L i t . m.p.  m.p.  by the method of Smith-  l£0-l£l°C.  1  ,  (14).  X. Large S c a l e .Methylation. of D-Mannose D i e t h y l M e r c a p t a l D-Mannose d i e t h y l m e r c a p t a l  (2,1  gm.)  was  methylated  an e x a c t l y s i m i l a r manner to D-glucose mercaptal, y i e l d i n g syrup  (2.21  gm.)  f r a c t i o n and  which was  in  a  f r a c t i o n a t e d i n t o a mercaptal -  a non-mercaptal f r a c t i o n as b e f o r e .  the mercaptal f r a c t i o n y i e l d e d a syrup  (0.79  tograms were run on t h i s syrup as b e f o r e .  H y d r o l y s i s of  gm.). One  Two  detected  Iodine yapour gave negative r e s u l t s , , whereas the other  chromawith detected  w i t h p - a n i s i d i n e h y d r o c h l o r i d e gave three d i s c r e t e spots o f R 's F  0.023,  0.08  and  0.20  and  a trailing  spot of R  F  range  0.£0-0.80. The mannose mercaptal arated and The  f r a c t i o n h y d r o l y s a t e was  sep-  the f r a c t i o n s I n v e s t i g a t e d e x a c t l y as f o r D-glucose.  r e s u l t s are g i v e n i n Table  VII.  28  Table V I I  (1:1)  Hydrocellulose C l a s s i f i c a t i o n Tube No. Wt. (mgm.)  Column  M  2  Rp(MEK) $ 0 C H  0  D Hexo.se  200-225  7  Monomethyl A  ll|2ri7^  107  Monomethyl B  102-139  53  .Monomethyl C*  89-99  9  Monomethyl D  83-87  .3  Dimethyl A Dimethyl B  3$-kl.  Trimethyl A  13-22  Trimethyl B  7-11  -.  -  0.023  +30°(H 0) 2  0..-08  15.4  09  15.3  +17o3°(H 0)  Go  +11.6°(MeOH)  0.13  -  6.15  -  2  •-  3  27  +26°.(Me OH)  .0,23  28.1  32  +59°(MeOH)  .0.28  27.2  ii+l  +38.3°(H 0)  0.53  34-.1  208  +36oO°(MeOH)  0.75  3^.1.  2  C l a s s i f i c a t i o n i s based on Rp v a l u e s o n l y and Is c onf irmat i o n .  subj ect t o  All., the above f r a c t i o n s were found t o be chromatographic a l l y pure except f o r some overlap: between T r i m e t h y l s A and B. XI. P e r i o d a t e O x i d a t i o n o f Mannose Monomethyl A. F r a c t i o n .Solutions c o n t a i n i n g monomethyl A (21.76 mgm., 6.112 mmole.) and sodium metaperiodate  (103.2 mgm., O.I4.82 mmole.)  were mixed and immediately made up t o 50 ml, w i t h d i s t i l l e d water and maintained a t 20°C.  Aliquots  (5 ml.)  were, withdrawn  at i n t e r v a l s and excess sodium b i c a r b o n a t e and potassium added > the s o l u t i o n s being l e f t complete  iodine formation.  determined  t o stand f o r l 5 minutes  iodide t o allow  ..Consumption of p e r i o d a t e was then  by adding a measured excess o f 0.1N sodium a r s e n i t e  s o l u t i o n and b a c k - t i t r a t i n g w i t h 0.1N i o d i n e s o l u t i o n  (9)  . When  p e r l o d a t e consumption had reached a constant v a l u e j formic  acid  p r o d u c t i o n was determined by n e u t r a l i s i n g an a l i q u o t t o methyl red  with standard a l k a l i . (9)  dime-done' reagent yield  A f u r t h e r a l i q u o t was t r e a t e d w i t h  to determine formaldehyde-, but f a i l e d t o  any p r e c i p i t a t e even a f t e r prolonged s t a n d i n g .  r e s u l t s are tabulated  The  below.  A. Perlodate Consumption 10  $  Time (minutes) Consumption  (mmoles.)  Consumption  (moles p e r mole) 3.60  B. Formic A c i d C. Formaldehyde XII.  O.40I4. O.lj.10 O.lp.3 Cl-pi}.  O.I4.O3 mmole.  3.70  O.Ip.7  O.lp.7  3.73  3.73  Perlodate O x i d a t i o n of Mannose Monomethyl,B. F r a c t i o n B ( 1 6 . 2 mgm.,  0.08ij. mmole.) was t r e a t e d w i t h  0 . 2 9 4 mmole.) e x a c t l y as b e f o r e ,  following r e s u l t s being obtained.  A. P e r l o d a t e  Consumption  (minutes)  $  Consumption (mmoles.) Consumption B  3.69  120  ( 3 . 6 moles p e r mole sugar.)  sodium metaperiodate ( 6 2 . 8 mgm.,  Time  3.66  60  None.  Monomethyl  the  30  1$  10  l£  30  60  90  120  0 . 0 3 0 . 1 3 0„l£ 0 . 1 9 0 . 2 3 0.26 0 . 2 6  (moles p e r mole) O.36 \ . $ $ 1 . 7 9 2.26 2 „ 7 4 3=09 3 . 0 9  * Formic A c i d  C. Formaldehyde  0.2lj.2 mmole. None.  ( 2 . 8 8 moles p e r mole sugar.)  The v a l u e s obtained i n XI and X I I ;are compared w i t h the t h e o r e t i c a l v a l u e s f o r the monomethyl mannoses in. Table VIII. Table V I I I T h e o r e t i c a l and Obtained R e s u l t s of P e r l o d a t e O x i d a t i o n of Monomethyl Mannoses Monomethyl Mannose  Moles P e r l o d a t e Consumed  Moles: Formic A c i d Produced  Moles Formaldehyde Produced  2- 0-methyl  3-0  2.0  1.0  3- 0-methyl  3.0  2.0  1.0  ij.-0-methyl  3.0  2.0  1.0  £-0-methyl  3-0  3.0  0.0.  6-0-methyl  i{..0  If. 0  0.0  Monomethyl A  3.7  3.6  0.0  Monomethyl B  3°1  2.9  0.0  XIII.  P r e p a r a t i o n of D e r i v a t i v e s of Monomethyls A and Treatment of the above sugars with  by the method of H a m i l t o n ^  B  phenylhydrazine  yielded c r y s t a l l i n e  phenylosazones.  T h e i r m e l t i n g p o i n t s are- co mpared below w i t h those of the c o r r e spending methyl glucose phenylosazones  which are i d en- -•  t i c a l i n s t r u c t u r e w i t h the 6-0-methyl- and  £-0-methyl-  D-mannose phenylosazones„  31 M.p.  Qsazone Monomethyl A  l8l-i85°c.  6 -0 -me thy 1 -D-g l u co s e  181|-187°G  Monomethyl B  l26-130°Go  5~ p_-rae thy 1-D-glue ose XIV.  120°C  0  (11)  (15)  o  Large S c a l e M e t h y l a t i o n of L-ArablnOse L-Arabinose  d i e t h y l mercaptal  ated by the same procedure  as b e f o r e .  y i e l d e d a syrup  (3.0 gm.) was methyl-  as f o r the D-glucose  m e r c a p t a l s , y i e l d i n g a syrup fractionated  D i e t h y l Mercaptal  and D-mannose  (2.757 gm.) which was c r u d e l y  H y d r o l y s i s of the m e r c a p t a l  fraction  (0.863 gm.) which when chromatographed i n  n-butanol-ethanol-water-ammonia (liO :10 :li9:1) gave no spots w i t h i o d i n e vapour and seven spots with p - a n i s i d i n e c h l o r i d e of R ' s 0.18, G  The  0.22,  0.25,  0.33,  0.37,  hydro-  0.39 and 0.1x5.  arabinose m e r c a p t a l f r a c t i o n h y d r o l y s a t e ' was  streaked on the s t a r t i n g l i n e s of sheets of Whatman No. 3 MM paper which had been p r e - r u n i n n-butanol-ethanol-water-ammonia. The l o a d o f m a t e r i a l was approximately 3 mgm. p e r cm. of paper width.  The s t r i p s were developed  solvent.  f o r l 5 hours u s i n g the same  Marker s t r i p s . 1.5 cm. wide were then cut from the  edges o f the d r i e d  developed  chromatograms.  D e t e c t i o n of these  with p - a n i s i d i n e h y d r o c h l o r i d e l o c a t e d the zones c o n t a i n i n g products.  The products were recovered by S o x h l e t e x t r a c t i o n of  the separated zones u s i n g $% aqueous acetone. R o t a t i o n s , methoxyls and Rp v a l u e s were determined i n Table IX.  as b e f o r e and are g i v e n  32 Table IX Arabinose F r a c t i o n s Separated on Whatman Mb. 3MM Wt. C l a s s i n e at Ion (mm.) Monomethyl A.'  r  £.6  20 D +106°(H 0) [oc}  2  Paper Rp(MEK)  % OCH  3 -~  0.09  Monomethyl B  13.4  +^2.5'°(H20)  0.16,  18.5  Monomethyl C  1.8. $  +37°(H 0)  0.23  16.6  Dimethyl A  914  +£8°(H 0)  c a 0 . 4 l (Trails.)  33.9  Dimethyl B  147.9  +77°(H 0)  caO.^.O ( T r a i l s )  36.1  Dimethyl C  243 »2  + 0°(MeOH)  2  2  2  0.80  34o4  C a l c u l a t e d methoxyl v a l u e s f o r mono- and d i m e t h y l pentoses r e s p e c t i v e l y are 18.9 and 3 4 ° 8 $ . C l a s s i f i c a t i o n , of t h i s product i s based on Rp o n l y . A l l the above f r a c t i o n s were found to be chromatographic a l l y pure except Dimethyl B which was an o v e r l a p f r a c t i o n of two components which f a i l e d  t o separate.  The  monomethyl f r a c t i o n s were*not I n v e s t i g a t e d f u r t h e r s i n c e p r e sent i n only n e g l i g i b l e amounts.  33 BIBLIOGRAPHY 1. Barker, S.A., Bourne, E . J . and Whiff en,, D.H. J . Chem. Soc. 3865. 1 9 5 2 . 2.  C l a r k , E.P.  Semimicro Q u a n t i t a t i v e Organic A n a l y s i s .  Academic Press Inc., New York, 191+3. 3.  Dutton, G.G.S.  It. F i s c h e r , E .  P e r s o n a l Communication.  Ber., 2 7 : 6 7 3 . I89I+.  5.  Greeriway, R.M., Kent, P.W. and Whitehouse> ,M.W. (London) 6 , S u p p l . No. 1 : 6 5 . 1 9 5 3 . 6 . Hamilton, R.H. J . Am. Chem. Soc. 56:1+87. 1931+.  Research  7. H e l f e r i c h , B. In Advances i n Carbohydrate Chemistry, 3 , ed. C.S. Hudson. Academic Press Inc., New York.  191+8.  8.  H i r s t , E.L. and Jones, -J.K.N. In D i s c u s s i o n s of the Faraday S o c i e t y 7, Chromatographic A n a l y s i s . .Gurney :and Jackson> London. 191+9 =  9.  Jackson, E.L. I n Organic R e a c t i o n s , 2 , ed. R. Adams.. John Wiley and Sons-, Inc., New York. 191+2+.  1 0 . Levene, P.A. and Meyer, G.M.  J . B i o l . Chem. 7l+:695. 1 9 2 7 .  1 1 . Levene, P.A. and Raymond, A.L. 12.  L i e s e r , T. and Leckzyck,, E.  13.  M a r t i n , A.J.P. and Synge, R.L.M.  ll+. M i t t s , E. and Hixori> R.M.  J . B i o l . Chem, 9 7 : 7 5 l . 1 9 3 2 .  Ann. 5 1 1 : 1 3 7 . 1 9 3 4 . Biochem. J . 3 5 : 1 3 5 8 . 191+1.  J . Am. Chem, S,oe. 66:1+83. 191+1+.  16.  P e r c i v a l , E.E. and P e r c i v a l , E.G.V. J . Chem. Soc. 1 3 9 8 . 1935. P u r d i e , T. and I r v i n e , J„C. J . Chem. Soc. 8 3 : 1 0 2 1 . 1 9 0 3 .  17.  Smith, F .  18.  Sugihara, J,M. In Advances In Carbohydrate Chemistry, 8 , ed. C„S. Hudson and M.L. Wolfrom, Academic Press I n c . , New York.- 1 9 5 3 .  15.  J , Chem. Soc, 7 5 3 . 1939.  19. Wolfrom, ,M.L.<, and B i n k l e y , W.W,. Chromatography' of Sugars arid R e l a t e d Substances. Sugar Research Foundation, Inc., New York. 191+8. 20,  ZInner, H.  Angew. Chem. 69s238,. 1957.  35  APPENDIX A Diagram o f Chrptnatographed. Products Methyl  of Methylations i n  Iodide  Start  Unlaiown P o l a r Products  Mercaotals  Solvent Front  APPENDIX B Diagram o f  CQiromator-raphed H y d r o l y s a t e s i n Methyl  Iodide  from  Methylation3  .  Start  Unchanged Sugars  Monomethyl Sugars  i-'olymethyl  Solvent Front  APPENDIX C Diagram o f Chromatographed Products  o f Methylations i n  T e t rahydro f u r a n  Start  Unlmown P o l a Products  Mercaptals  T h i s chows products  at 50  only,  Solvent Front  APPENDIX D DiaF.ran o f Chroiaatoprraphca H j d r o I " s a t o s from Methyl.itions i n Tet rahydrofuran  D-Glucose D-Mannose D-Galactose  L-Arabinose Start  0  0 0  0  0  0 o  0  0 0  Monometh3 l r  Sugars  o 0 0  0  Unchanged Sugars  Polymethyl Sugars  0  Solvent Front T h i s shows p r o d u c t s at 50  only.  APPENDIX E Infra-Red S p e c t r a o f D i e t h y l  Mercaptals  APPENDIX A Diagram o f Chromatographed Products o f M e t h y l a t i o n s i n Methyl  Iodide  Start  0 0  0  0  0  0  0A  o  00 00  0  0 o  o  0  o  Unknown P o l a r Products  Mercaptals.  0  Solvent Front  APPENDIX B Diagram, o f Chromatographed H y d r o l y s a t e s from M e t h y l a t i o n s i n Methyl  Iodide  Start  o  0  0  Unchanged Sugars  0 Monomethyl Sugars  0  0  Polymethyl Sugars  0 0 Solvent Front  APPENDIX C Diagram o f OhroEatographed P r o d u c t g o f M e t h y l a t i o n s i n  *  Tetrahydrofuran  Start  Unknown P o l a r Products  Mercaptals  T h i s shows p r o d u c t s  at 50  Solvent Front only*  APPENDIX D Diagram o f Chro mat o graphed H y d r o l y s a t e s from M e t h y l a t i o n s i n Tetrahydrofuran  Start  Unchanged Sugars  Monomethyl Sugars  Polymethyl Sugars  Solvent Front T h i s etiows p r o d u c t s at 50  only.  APPENDIX E Infra-Red S p e c t r a o f D i e t h y l Mercaptals  D-G-lucose  D-Galactose  D-Mannose  L-Arabinose  3200  2400  1900  1700  Wave numbers (cm~^) The i n f r a - r e d a b s o r p t i o n was measured i n a Perkin-Elmer Recording Spectrophotometer pellets'!  u s i n g p r e s s e d potassium bromide  

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