This paper represents part of a thesis submitted by D. Beith-Halahmi in partial fulfilment of the requirements for the degree of Doctor of Philosophy from The Weizmarm Institute of Science,
Synthesis of oligosaccharins: a chemical synthesis of propylO-β-d-galactopyranosyl-(1 → 2)-O-α-d-xylopyranosyl-(1 → 6)-O-β-d-glucopyranosyl-(1 → 4)-β-d-glucopyranoside
✍ Scribed by Arlette Wotovic; Jean-Claude Jacquinet; Pierre Sinay¨
- Publisher
- Elsevier Science
- Year
- 1990
- Tongue
- English
- Weight
- 839 KB
- Volume
- 205
- Category
- Article
- ISSN
- 0008-6215
No coin nor oath required. For personal study only.
✦ Synopsis
Condensation of allyl 3,4-di-O-benzyl-beta-D-xylopyranoside with 2-O-acetyl-3,4,6-tri-O-benzyl-alpha-D-galactopyranosyl chloride in dichloromethane in the presence of silver triflate gave allyl 2-O-(2-O-acetyl-3,4-6-tri-O-benzyl-beta-D-galactopyranosyl)-3,4-di-O benzyl-beta-D-xylopyranoside (7, 83%). Compound 7 was converted in five steps into 2-O-(2-O-acetyl-3,4-6-tri-O-benzyl-beta-D-xylopyranosyl bromide (13), which was condensed immediately with allyl 2,3,6-tri-O-acetyl-4-O-(2,3,di-O-acetyl-beta-D-glucopyranosyl)-beta-D- glucopyranoside to give crystalline allyl O-(2-O-acetyl-3,4,6-tri-O-benzyl-beta-D-galactopyranosyl)- (1----2)-O-(3,4,-di-O-benzyl-alpha-D-xylopyranosyl)-(1----6)-O-(2,3,-di- O-acetyl-beta-D-glucopyranosyl)-(1----4)-2,3,6-tri-O-acetyl-beta-D-gluco pyranoside (23, 50%). O-Deacylation of 23 followed by catalytic hydrogenolysis gave the title glycoside.
📜 SIMILAR VOLUMES
Recent years have seen a remarkable surge of interest in the study of U-Lfucosyltransferases. Of these L-fucosyltransferases, the enzyme (143)~a+fucosyltransferase has attracted a great deal of clinical interest as a potential tumor marker. This enzyme catalyzes the transfer of an L-fucosyl group f
Halide-assisted glycosyIation, using a non-p~icipating Z-substituent (benzyl) in the glycosyl halide, was used to obtain the ~-D-gaiactosyl linkage and silver triflate promotion with a participating 2-substituent (benzoyl) was used to obtain the /3-D-galactosyl linkage in a facile synthesis of the t
Ally1 4-0-(4-O-acetyl-2-O-benzoyl-3,6-di-O-benzyl-~-D-galactopyranosyl)-2-0-benzoyl-3,6-di-O-benzyl-a-D-galactopyranoside was 0-deallylated to give the 1-hydroxy derivative, and this was converted into the corresponding l-O-(Nphenylcarbamoyl) derivative, treatment of which with dry HCl produced the