Dec. 5, 1956 [CONTRIBUTION
STRUCTURE OF CORNHULLHEMICELLULOSE FROM THE
6169
DEPARTMENT OF AGRICULTURAL BIOCHEMISTRY, UNIVERSITY OF MINNESOTA]
Structure of Corn Hull Hemicellulose. 11. Identification of the a- and P-Forms of Methyl 2-0-[Methyl (2,3,4-Tri-O-acetyl-a-D-glucopyranosyl)-uronate ]-3,4-di-O-acetylD-xylopyranoside ls2
BY R. MONTGOMERY, F. SMITHAND H. C. SRIVASTAVA RECEIVEDMAY2, 1956 The methyl ester methyl glycoside pentaacetate (acetate I), m.p. 257', derived from the aldobiouronic acid obtained by hydrolysis of the corn hull hemicellulose has been shown t o be methyl 2-0- [methyl (2,3,4-tri-O-acetyl-a-~-glucopyranosyl) uronate]-3,4-di-O-acetyl-~-~-xylopyranoside (I). Methylation of I followed by reduction and remethylation gave methyl 2-0-(2,3,4,6-tetra-O-methyl-a-~-glucopyranosyl)-3,4-d~-0-methyl-~-~-xylopyranoside (V) which upon hydrolysis afforded 2,3,4,6-tetra-0-methyl-~-glucose and 3,4-di-O-methyl-~-xylose. The biose linkage in both acetates I and I1 has been shown by enzymatic studies to be of the a-type.
Corn hull hemicellulose3 was shown in Part I4to biose link. To resolve this problem, I and I1 were give on graded hydrolysis followed by treatment reduced with lithium aluminum hydride in tetrawith methanolic hydrogen chloride and acetyla- hydrofuran with simultaneous deacetylation in ortion two methyl ester methyl aldobiouronoside der to obtain the methyl glycosides of the correpentaacetates (I, m.p. 257', [ a ] f103' ~ (CHCI,); CH,OH H and 11, m.p. 180°, [ a ] 4-163' ~ (CHCI,)). One of these acetates (11) was shown to be methyl 2-0HO H l g H , O M e [methyl (2,3,4-tri-O-acetyl-a-~-glucopyranosyl)-uronate]-3,4-di-O-acetyl-~-xylopyranoside, the a-biH H01 ose linkage being indicated by a high positive rotaL-o-tion. 111, &anomer a-glucosidase D-glucose This paper is concerned with the elucidation of IV, a-anomer methyl D-xyloside the structure of the acetate I which is now shown to LiAlH, be methyl 2-0- [methyl (2,3,4-tri-O-acety~-a-D-ghlcopyranosyl) - uronate] -3,4-di-O-acetyl-@-D-xyloCOOMe, pyranoside by the following experimental evidence. Reduction of I with lithium aluminum hydride and AcO OAc H Ac:QH,OOAc Me H I concomitant deacetylation gave the methyl glycoside I11 of the corresponding neutral disaccharide H AcOl H which upon hydrolysis was found by paper chroL O A matography to give glucose and xylose. acetate I , @-anomer, [ a ] +103' ~ (CHCls) Methylation of I with Purdie reagents followed acetate 11, a-anomer, [ a ] +163' ~ (CHCIJ by reduction with lithium aluminum hydridebs6and 1, methylation remethylation gave methyl 2-0-(2,3,4,6-tetra-O2, reduction methyl - a-D- glucopyranosyl) - 3,4 - di - 0 methyl3, remethylation D-xylopyranoside (V) which afforded on hydrolysis CH,OMe H the characteristic crystalline 2,3,4,6-tetra-O-methylD-glucose' and 3,4-di-O-methyl-~-xylose,the latter being identified as 3,4-di-O-methyl-~-xylon0-6M e0 M e'Q 0 H,OMe lactone.8 Since the two fully methylated disaccharide H Me01 H -_ 1 methyl glycosides, V and VI, obtained from the two V, 8-anomer, [ a ] +86' ~ (CHaOH) corresponding acetates (I and 11) by successive VI, a-anomer, [ a ] +146' ~ (CH,OH) methylation, reduction and remethylation, were different and yet underwent hydrolysis to give the Hydrol. same methylated fragments, namely, 2,3,4,6-tetra2,3,4,6-tetra-0-methyl-~-glucose 0-methyl-D-glucose and 3,4-di-O-methyl-~-xylose, 3.4-di-0-met h yl-D-xylose it was apparent that I and I1 were isomers. It Fig. 1. was not clear, however, whether the isomerization resided a t CI of the xylose moiety or a t the sponding neutral disaccharides I11 and IV. The latter were then treated with a- and with @-gluco(1) Paper No. 3516, Scientific Journal Series, Minnesota Agricul~ i d a s e . ~While the two disaccharide methyl glycotural Experiment Station, University of Minnesota. (2) This research was done under contract with the U. S. Departsides I11 and I V derived from I and 11, respecment of Agriculture and authorized by the Research and Marketing tively, were unaffected by @-glucosidase,they were Act of 1946. The contract was supervised by the Northern Utilizacleaved by a-glucosidase to give D-glucose and ption Research Branch of the Agricultural Research Service. and a-methyl D-xyloside, respectively, as shown by (3) M. J. Wolf, M. M. MacMasters, John A. Cannon, E. C. Rosewall and C. E. Rist. C e r e d Chem., 80, 451 (1953). chromatographic analysis and glass paper electro(4) R. Montgomery, F.Smith and H. C. Srivastava, TAISJOURNAL, phoresis. lo The linkage between the glucuronic acid 78, 2837 (1956).
'0
'G t
-
!
A
4
( 5 ) M. Abdel-Akher and F. Smith, Nalrrrc, 166, 1037 (1950). (6) B. Lythgoe and S. Trippett, J . Chem. SOC.,1983 (1950).
(7) J. C. Irvine and J. W. H. Oldham, i b i d . , 119, 1744 (1921). S.P. James and F. Smith, ibid., 739 (1945).
(8)
(9) W. L. Porter and N. Hoban, Anal. Chem., 26, 1846 (1954) (10) D R. Briggs, E. F. Garner, R. Montgomery and F. Smith, ibid., 18, 1333 (1956): D. R. Briggs, E. F. Garner and F. Smith, Nature, 178, 154 (1956).
R. MONTGOMERY, F. SMITHAND H. C. SRIVASTAVA
6170
Vol. 78
Hydrolysis of Methyl 2-0-(2,3,4,6-Tetra-O-methyl-a-~ and the xylose moiety in I and I1 is therefore of the a glucopyranosyl)-3,4-di-0-methyl-p-~-xyylopyranoside(V).type. It follows that the configuration of the glyco- A solution of the methylated disaccharide (185 mgb) in -V sidic methoxyl group in I, on the basis of its lower sulfuric acid (10 ml.) was heated for 20 hours at 100 . The rotation, is p whereas that of I1 is a. The acetate solution was passed through Duolite A4 resin and evaporated I is therefore designated as methyl 2-0- [methyl in DUCUO to a sirup. On chromatographing the sirup using (%,3,4-tri-O-acetyl-a - D-glucopyranosyl) -uronate]- benzene: ethanol: 27, ammonium hydroxide (200:47: 15)16as irrigating solvent and p-anisidine trichloroacetate" a s 3,4-di-O-acetyl-/3-~-xylopyranoside and I1 is desig- the the spray reagent, three spots having these XTG (tetra-0nated as methyl 2-0- [methyl (2,3,4,-tri-O-acetyl-a- methyl-D-glucose) values were obtained: 0.31, 0.99, 1.12. ~-glucopyranosyl)-uronate] -3,4-di-O-acetyl-a-D- A reference sample of 3,4-di-0-methyl-D-xylose showed RTG xylopyranoside. These facts prove that the parent 0.31. The spot with R w 1.12 gave a strong pink color and probably due to the reducing methylated disaccharidelB aldobiouronic acid is 2-0-a-~-glucopyranosyluronicwas since elution of i t from the paper followed by hydrolysis gave acid-D-xylopyranose, a compound reportedll to be spots corresponding to 2,3,4,6-tetra-O-methylglucoseand present in a mixture of aldobiouronic acids isolated 3,4-di-O-methylxylose. The hydrolyzate of the methylated from corn cobs; the same aldobiouronic acid has disaccharide was therefore rehydrolyzed with 2%' sulfuric acid 5 ml.) on the steam-bath for 10 hours and the material also been obtained from chagual gum12and there is (isolated as before. The hydrolyzate now gave only two evidence for it in oat hull h e r n i c e l l u l ~ s e . ~ ~ ~ ~ ~ spots corresponding t o 2,3,4,6-tetra-O-tnethylglucoseand 3,4-di-O-methylxylose on chromatographic analysis. The mixture of 2,3,4,6-tetra-0-metliyl-~-glucosc and 3,4Methylation of Methyl 2 - 0 [Methyl (2,3,4-Tri-O-acetyl-adi-0-methyl-D-xylose was resolved on sheets of Whatman D-glucopyranosy1)-uronate]-3,4-di-O-acetyl- p - D - xylopyrano- No. 1 paper using methyl ethyl ketone:water19 azeotrope as side (Acetate I).-The acetate I , 4 m.p. 257' (570 mg.), was the irrigating solvent. suspended in cold ethanol (35 ml.) and N potassium hydroxIdentification of 2,3,4,6-Tetra-0-methyl-~-glucose.-Thc ide ( 5 nil.) added dropwise. T h e solution was allowed t o at- 2,3,4,6-tetra-0-methylglucose component obtained as a tain room temperature gradually and then kept overnight. sirup (63 mg.) crystallized on nucleation and had n1.p. and In order to dissolve all the substance, acetone (10 ml.) was mixed m.p. 89-90', [ ( Y ] ~ ~+87" D ( G 0.3) in ethanol (after two added and the temperature raised to 50-60". The reaction recrystallizations from ether-petroleum ether). mixture mas cooled t o room temperature and allowed t o Identification of 3,4-Di-O-methyl-~-xylose.-The 3,4-distand for 8 hours. Acetone and ethanol were distilled off 0-methylxylose component, isolated as a sirup (56 mg.) havwith simultaneous addition of water. The resulting aqueous ing [ a I z 24-22' ~ (c 0.2) in methanol, was oxidized with brosolution was passed through Amberlite IR120 and the acidic mine for 5 days. The excess of bromine was removed by aeraeffluent evaporated iit zlucuo to give a white glass. This was tion and the solution neutralized (Ag2C03). The solution, dissolved in dry methanol (5 ml.) and methylated with after filtration, was passed through Amberlite IR-120 and methyl iodide (10 ml.) and silver oxide (5 g.) in the usual concentrated in zacuo to a sirup. Distillation of the latter, manner. On filtration and evaporation of the filtrate, a b.p. (bath temp.) 80-90" (0.01 mm.), gave a colorless sirtip pale yellow sirup was obtained which was remethylated by which crystallized on nucleation. The 3,4-di-O-methyl-Ddissolving it in methanol (1 ml.) and treating i t with methyl xylono-&lactone thus obtained had m.p. and mixed m.p. iodide (10 ml.) and silver oxide (3 g.). The product, now sol- 65-67' and I a ] 2 4 D -22" (6 0.3, equilibrium value) in water uble in methyl iodide, was methylated a third time with Pur(after purification by sublimation). die reagents to give the methylated methyl aldobiouronoside Isolation of the CY- and 0-Forms of Methyl ~ - O - ( ~ - D - G I U methyl ester as a sirup (448 mg.). copyranosy1)-D-xy1opyranoside.-The acetate I (50 mg.) was Isolation of Methyl 2-0-(2,3,4,6-Tetra-O-methyl-a-~suspended in dry tetrahydrofuran ( 5 ml.) and added graduglucopyranosyl)-3,4-di-O-methyl-p-~-xylopyranoside(V).ally to a suspension of lithium aluminum hydride (100 mg .) The methylated methyl aldobiouronoside methyl ester (448 in tetrahydrofuran (5 ml.). The mixture was refluxed for 3 mg.) obtained in the previous experiment was dissolved in hours, cooled, filtered and the filtrate after acidification with dry ether (20 ml.) and the solution added dropwise to a sus- acetic acid evaporated in vacuo to give methyl 2-0-(a-Dpension of lithium aluminum hydride (500 mg.) in ether (10 glucopyraiiosy1)-&D-xylopyranosirle (111) as a colorless sirup ml.). The mixture was refluxed for 0.5 hour and the ex(20 mg.). A portion of it was hydrolyzed with N sulfuric cess of reagent destroyed by ethyl acetate. After acidifica- acid in a sealed tube for 6 hours and the reaction mixture, aftion with glacial acetic acid, the reaction mixture was evapter neutralization (BaC03),mas concentrated in zracuo to give orated in v u u o and the product acetylated's with acetic an- a sirup which was found on chromatographic analysis to be hydride (15 ml.) and fused sodium acetate (500 mg.) at 110composed only of glucose and xylose. 120' for 3 hours. The excess of acetic anhydride was reThe acetate 11, Rhich was completely soluble in tetrahymoved by distillation and the residue acidified with N hydrofuran, was reduced with lithium aluminum hydride in the drochloric acid. The resulting aqueous solution was ex- same manner to give methyl 2-O-(~-D-glUCOp?-raI?osyl)-atracted with chloroform and the chloroform extract, after D-xylopyranoside (IV). washing with water and drying (NarSOa), was evaporated in Action of CY- and 0-Glucosidase on the a-(IV) and 0-(III) Z J U C U Oto a light-colored viscous sirup (332 mg.) which showed Forms of Methyl 2-0-(a-D-Glucopyranosy1)-D-xylopyrano[a]"D +75' in methanol (c 3.3). This was saponified by side .-The disaccharide methyl glycosides derived from acedissolving it in methanol (20 ml.) and adding N potassium tates I and I1 as described above were each dissolved in SOhydroxide (5 ml.) and heating the solution at 80-90" for 2 dium acetate buffer (PH 5.0) and incubated in m . p . tubes hours. The solution was then passed successively through with ~-glucosidasegfor periods of 24 and 72 hours. ChroniaAmberlite IR-120 and Duolite A4 resins t o remove the cattographic analysis showed t h a t the glycosides mere unafions and any unchanged aldobiouronic acid. The effluent fected. Control experiments showed under the same condiwas evaporated in vucuo to give a colorless viscous sirup (280 tions cellobiose readily afforded glucose while maltose was mg.). Three methylations of this sirup with Purdie reunaffected. agents afforded methyl 2-0-(2,3,4,6-tetra-O-methyl-a-~-glu- When disaccharide methyl glycosides (111 and 1 V ) in copyranosyl)-3,4-di-0-methyl-~-~-xylopyranoside ( V ) as a aqueous solution Fvere incubated with a-glucosidase, they pale yellow mobile sirup (266 mg.), b.p. (bath temp.) 160were cleaved into u-glucose and p- and a-methyl D-xyloside, 170' (0.005 mm.), [ajz 2 +86" ~ (c 3.7) in methanol. respectively, as indicated by paper chromatographg- using ilnal. Calcd. for C1&&: OCH3,52.9. Found: OCH3, pyridine-ethyl acetate-water (1:2.5:3.5)20and by glass pa50.2.
Experimental
..-. .
.-
___
(11) R. L. Whistler and L. Hough, THJSJOWRNAL, 76, 4916 (1953). (12) J . IC. Hamilton, F. Smith and D. R. Spriestersbach, i b i d . , in press. (13) E. L. Falconer and G . A. Adams. Gait. J . Chem., 34, 336 (195ti). (14) 0 . H a y a n d F. Smith, unpublished work. (15) H. J . ILlosterman, F.Smith, THISJOURNAL, 74, 5336 (1952).
(16) G. A. Adams, Carr. J . C h e m . , 33, 56 (1955). (17) L. Hough, J. K. N. Jones and W. H. Wadman. J . C k e m . soc., 1702 (1950). (18) Cj.A. R . N. Gorrod and J . K . N.Jones. ibid., 2522 (1954). (19) L. Boggs, L. S. Cuendet, I . Ehrenthal, R . Koch and F. Smith, Natirre, 166, 520 (1950). (20) E. F. McFarren, K . Brand and H. R. Kutkowski, A n a l . Chem., a3, 1146 (1951).
FURTHER ATTEMPTSTO
Dec. 5, 1956
6171
PREPARE 3,4-DIMETHYLENETHIOPHANE
per electrophoresis’o (0.1 M borate buffer). Under the same conditions maltose readily gave glucose while cellobiose remained unchanged.
supply of the corn hull hemicellulose through the courtesy of D ~ M. ~ .J. Wolf and M. M. M ~ ~ -
Acknowledgment.-The authors thank the Northern Utilization Research Branch for the
Masters*
[CONTRIBUTION FROM
THE
ST. PAUL,MINNESOTA
NOYES CHEMICAL LABORATORY, UNIVERSITY
OF
ILLINOIS]
Further Attempts to Prepare 3,4-Dimethylenethiophane and its Sulfone1 BY
c. s. MARVEL,ROBERTM. NOWAK* AND JAMES
ECONOMY
RECEIVED JUNE 18, 1956 The Hofmann decomposition of the quaternary ammonium hydroxide of 3-methylene-4-dimethylaminomethylthiophane at room temperature and 5 mm. pressure has been found to give the rearranged product 3,4-dimethylthiophene in 21% yield and no 3,4-dimethylenethiophane. I t has also been shown that the pyrolysis of 3,4-bis-(acetoxymethyl)-thiophanesulfone a t 520 f 5” does not lead to 3,4-dimethylenethiophanesulfone but causes decomposition with much charring to give poor yields of two products that have been tentatively identified as 3-methylene-4-acetoxymethylthiophane sulfone and 2-methyl-
3-acetoxymethyl-1,3-butadiene.
that the rearrangement of the dimethylenethiophane to dimethylthiophene occurs with ease and that the higher temperature involved in the earlier pyrolysis of the diacetate was not necessarily the cause of the rearrangement. CH3 CHS
A previous attempt to prepare 3,4-dimethylenethiophane (I) by the pyrolysis of 3,4-bis-(acetoxymethyl)-thiophane (11) yielded only the 3,4dimethylthiophene (111) and none of the desired CHz CHz
II
c-c II I I
CHz CHz
\s/ I
CHzOCOCH3
I CH-----CH I
CHz
CHzOCOCH,
I I
CHz
I 1 c-c
II
CH
II
CH
\S/
’S‘ I1
I11
pr~duct.~ It was thought that the rearrangement might have been caused by the high temperature encountered during the pyrolysis reaction and that the preparation of the dimethylenethiophane (I) might be accomplished if less vigorous conditions were used. It has now been shown that the Hofmann decomposition of the quaternary ammonium hydroxide of 3-methylene-4-dimethylaminomethylthiophane (VIII) a t room temperature also gives the rearranged thiophene isomer 111. The steps invoived in the preparation of the required quaternary ammonium hydroxide are outlined in the chart. In the conversion of the double ring compound VI1 to the methiodide, some methylation of the sulfur must have occurred since in the decomposition of the quaternary hydroxide in addition to 51.5% yield of the sulfur ring compound VI11 there was obtained a 23.5% yield of 1,3,4-trimethylpyrrole (IX). A third product was isolated which, while not completely characterized, appears t o be a methyl mercaptan adduct of the olefinic derivative VIII. The quaternary salt of the olefinic amine (VIII) was prepared, treated with silver oxide in water and allowed t o decompose to the olefin a t a temperature below 25’. The product, however, proved to be 3,4-dimethylthiophene (111). It is thus obvious (1) T h e work discussed herein was performed a s a p a r t of t h e synthetic rubber research project sponsored b y t h e Federal Facilities Corporation a n d t h e National Science Foundation. ( 2 ) T h i s paper represents p a r t of a thesis submitted by Robert M. Nowak t o t h e Graduate School, University of Illinois, in partial fulfillment of t h e degree of Doctor of Philosophy, 1956. (3) C. S hlarvel and I.: E. Ryder. Tr , THIS ~orlnlv.41.. 77. 66 (1955).
0
, \
cI ---c
I
CHz
CHz
I
70
hydrolysis
I
I
/
___f
I
-Hz0
’S‘
YO
C 1 H-~H
- C O ~-
I
\
I
CHI CHI
\ /
IV
s
v
CHI
I
IT
/ \
CHs
I I CH-CH I 1
N
I
CHz CHz
/ \
co co
CHz CHz
LiAIHl
c--
\s’
I
1
CH-CH CH2 I CHz 1
VI1
‘S/ CHz CHzN( CH3)2 I1 I
VI CH3 CHI
CHI CHI I1
I1
I1
II
c-c
CH CH I11
\s/
ring Another approach to a five-membered compound with 3.4-dimethvlene substitution was sought. 3,4-Diacetoxymethylthiophane (11) was prepared by modification and improvement of the method before3 and Oxidized with 30% hydrogen peroxide in acetic anhydride to give the
