Condensation of 2,4-di-O-acetyl-3,6-di-O-methyl-a-~glucopyranosyl bromide with either ally1 or benxyl2,4-di-0-methyl-cu+rhamnopyranoside in the presence of mercuric cyanide, followed by 0-deacetylation, gave the title oligosaccharides in excellent yields.
Synthesis of methyl 2,4-di-O-methyl-3-O-(2-O-methyl-α-l-rhamnopyranosyl)-α-l-rhamnopyranoside and methyl 2,4-di-O-methyl-3-O-[2-O-methyl-3-O-(2-O-methyl-α-l-fucopyranosyl)-α-l-rhamnopyranosyl]-α-l- rhamnopyranoside: di- and tri-saccharide segments of a phenolic glycolipid of Mycobacterium kansasii
✍ Scribed by Mukund K. Gurjar; K.Revathi Reddy
- Publisher
- Elsevier Science
- Year
- 1992
- Tongue
- English
- Weight
- 443 KB
- Volume
- 226
- Category
- Article
- ISSN
- 0008-6215
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✦ Synopsis
Syntheses of the title glycosides are described. The critical O-glycosylations were carried out in the presence of boron trifluoride etherate with a high degree of alpha-selectivity.
📜 SIMILAR VOLUMES
The title branched-trisaccharide derivatives (9 and 13) have been synthesised from methyl 2,3-O-(2-nitrobenzylidene)-a-L-rhamnopyranoside (2) using the 2nitrobenzylidene residue as a temporary blocking-group. Condensation of 2 with methyl (2,3,4-tri-O-acetyl-a-D-glucopyranosyl bromide)uronate afford
Allyl 4-O-benzyl-~-L-rhamnopyranoside was converted into allyl 4-O-benzyl-3-O-methyl-oeL-rhamnopyranoside and this was condensed with 2,3,4-tri-O-acetyl-~-L-rhamnopyranosyl chloride to give a disaccharide derivative which was converted into allyl 4 This disaccharide derivative was condensed with 2,
In a previous papeti in this series, we described the synthesis of L-fucosyldisaccharides having sulfate groups at C-3 or C-4. Such r\_-fucosyl-oligosaccharides occur naturally as a part of the structure of fucoidan, a sulfated L-fucose polysaccharide, know to possess anticoagulant acticity 3,4 This