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COhI1ZIUNICATIONS TO
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VOl. 84
THE ISOLATION AND SYNTHESIS OF THE METHYL ESTER-METHYL a-GLYCOSIDE OF
react with an excess of (methyl tri-0-acetyl-a-Dglucopyranosyluronate) bromide and mercuric cya~-O-@-D-GLUCURONOSYL-N-ACETYL-Dnide in a mixture of nitromethane and benzene GLUCOSAMINE (HYALOBIURONIC ACID)’ for 8 days. The resulting product was purified by Sir: chromatography on silicic acid, heated for 15 Polysaccharide components of animal connective min. with 60yGacetic acid, and acetylated with tissue, such as hyaluronic acid, chondroitin sul- acetic anhydride in pyridine solution, to give I1 fate and dermatan sulfate, are built of alternate in 427; over-all yield, m.p. 2;37 - 2 3 S o , [ c Y ] ~ ’ D+30° units of uronic acid and hexosamine linked a t posi- (c O.W, CHCl:{),identical with the product detions 4 and 3, respectively. Isolation of a 3 - 0 - scribed above. .InaZ. Calcd. for C26H&iN: C, 0-D-glucuronosyl-hexosamine disaccharide, chon- 49.13; H, 5.Si; OCH3, 9.7i. Found: C, 49.27; drosin, from chondroitin sulfate was reported H , 5.96: OCH3, 9.91. Reduction of I1 with lithalready in 1914,2 whereas a similar disaccharide, ium borohydride in tetrahydrofuran, followed by 3 - 0 - ( p - D - glucopyranosyluronic acid) - 2 - amino- acetylation, gave a product identical with VI, 8-deoxy-D-glucose (hyalobiuronic acid) (I) re- described below. cently has been isolated from hyaluronic acid. The product resulting from the reaction of V with We wish to report the first synthesis of this type equimolecular quantities of tetra-0-acetyl-a-Dof disaccharide, isolated as the fully acetylated glucopyranosyl bromide and mercuric cyanide in methyl ester-methyl-a-glycoside of I , namely, benzene-nitromethane a t 30’ for 3 days was demethyl 3-O-(methyl tri-0-acetyl-P-D-glucopyrano- acetylated catalytically with sodium methoxide, syluronate) -2 - acetamido -4,B-di-0- acetyl - 2 - deoxy- and heated with 6n7c acetic acid. After purifia-D-glucopyranoside (11). The same compound cation through a charcoal-Celite (1 : 1) column, I1 was obtained directly by degradative meth- methyl 3-0-(p-D-glucopyranosyl)-2-acetamido-2-deanolysis of hyaluronic acid, then by acetylation, oxy-a-D-ghcopyranoside (VI) was obtained in and from hyalobiuronic acid (I), by glycoside 35% yield, m.p. 252-254’; [(Y]~’D +44’ (c I.[)[), formation and acetylation. H20). &lnal. Calcd. for C15HeTOllN: C, 45.33; Dried hyaluronic acid (1.10 g.) from human H , 6.85. Found: C, 45.88; H , 7.13. Acetylation umbilical cord,j was refluxed with 6Yc methanolic of VI with acetic anhydride in pyridine solution hydrochloric acid for 24 hr. The resulting sirup, gave the hexa-0-acetyl derivative in 75% yield, treated with pyridine and acetic anhydride gave, m.p. 236-237’, [ C Y ] ? ~ D +21’ (c 1.11, CHC13). after purification by chromatography on silicic -1nal. Calcd. for C2iH39OliN: C, 49.92; H, 6.05. acid, 0.76 g. of crystalline material. Recrystalli- Found: C, 50.02; H , 6.08. zation afforded 0.22 g. of 11, m.p. 236-238’, [ a ] ” D Acknowledgement.-This work was supported 4-30’ (c 0.68, CHC13). *~lnal.Calcd. for C26H3701,X: C, 49.13; H, 5.87: N , 2.20; OCH3, 9.77. by research grants from the National Institute of Found: C, 49.19; H, 5.95; N, 2.33; OCHJ, Arthritis and Metabolic Diseases, Kational In10.36. Hydrolysis of I1 with barium methylate stitutes of Health, U. s. Public Health Service in methanol a t 0’ gave methyl 3-o-(p-D-glUCO- (Grant -1-3564) and from the National Science pyranosyluronic acid) -2 - acetamido - 2 - deoxy - a - D- Foundation (Grant 9-2312). The authors are glucopyranoside (111) in 95% yield, m.p. 207- very grateful to Dr. K. Meyer for the gift of N 210°, [ a ] =+31° (c 0.74, CH30H). Anal. Calcd. acetylhyalobiuronic acid. for C15H15012r\j’HzO: C, 41.96; H, 6.34. Found: (8) On leave of absence f r o m t h e Weizmann I n s t i t u t e o f Sciences C, 41.94, H, 6.40. Esterification of I11 with Rehovoth, Israel. diazomethane or methanolic hydrochloric acid DEPARTMENT OF BIOLOGICAL CHEMISTRY ASD MEDICISE afforded IV, identical with the compound de- HARVARD MEDICAL SCHOOL AND W. JEANLOZ GENERAL HOSPITAL ROGER scribed below. 3 - 0 - (,R - D - glucopyranosyluronic MASSACHUSETTS HAROLD M. FLOWER@ acid)-2-acetamido-2-deoxy-~-glucose,~ obtained by BOSTOX14, MASS. RECEIVED MAY19, 1962 N-acetylation of I , was refluxed with 1.5 N methanolic hydrochloric acid and gave, after purification by chromatography on silicic acid, methyl 3 - 0 - (methyl ,R - D - glucopyranosy1uronate)OF “SULFENE” TO KETENE 2 - acetamido - 8 - deoxy - a - D - glucopyranoside THE CYCLOADDITION DIETHYLACETAL (IV) in 50% yield, m.p. 223-225’, [ a ] ” D +16’ (c 1.09, CH30H). Acetylation of 1lr gave I1 in Sir : yield. Sulfenes as reactive intermediates have been Methyl 2 - acetamido - 4,6 - 0 - benzylidene - 2- proposed by various workers. Diphenylsulfene deoxy - (Y - D - gl~copyranoside~ (17) was allowed to was suggested as an intermediate in the reaction of diphenyldiazomethane with sulfur dioxide which (1) Amino Sugars X X X I I , a n d publication h-o, 313 of t h e R o b e r t W. Lovett Memorial Group f o r t h e S t u d y of Crippling Disease, decomposed to form tetraphenylethylene. LikeHarvard Medical School a t t h e Massachusetts General Hospital, wise a similar structure was postulated by KloosterBoston 14. ziel and Backer.2 “Methylenesulfene” (CH2= (2) J. Hebting, Biochem. Z . , 63, 353 (1914). SOz) was proposed by Hesse and Reichold3as formed (3) T. Isikawa, TGhoku J . E x p l l . M e d . , 63, 217 (1951). (4) M. M . R a p p o r t , B. Weissmann, A . Linker a n d K . Meyer, by the interaction of diazomethane with sulfur g4
N a f u v e , 168, 996 (19,51). ( 5 ) R . W. Jeanloz a n d E . Forchielli, J . B i d Chem., 186, 495 (1950). ( 6 ) B. Weissmann and K. Meyer, J . A m . Chem. Soc., 76, 17.53 (1954). (7) A. Seuberger, J . Chem. Soc , 20 (1901); I>. F. Wiggins, ibid., 18 (1947).
(1) H. Staudinger a n d F. Pfenninger, Ber., 49, 1941 (1916). (2) H . Kloosterziel a n d H . J. Backer, Rec. trau. chim., 71, 1235 (1952). (3) G. Hesse a n d E. Reichold, Bey., 90, 2106 (1957).
