title: Synthesis of di-O-glycosyl derivatives of methyl alpha-L-rhamnopyranoside.
abstract: The syntheses are described of 2,3-di-O-glycosyl derivatives (1-12) of methyl alpha-L-rhamnopyranoside where the glycosyl moieties are variously alpha-L-fucopyranose, beta-L-fucopyranose, beta-D-glucopyranose, alpha-D-mannopyranose, and alpha-L-rhamnopyranose. The syntheses involve stereoselective glycosylation of methyl 4-O-benzoyl-3-O-(2,3,4-tri-O-benzoyl-alpha-L- rhamnopyranosyl)-alpha-L-rhamnopyranoside (21), methyl 4-O-benzoyl-3-O-(2,3,4,6-tetra-O-benzoyl-alpha-D-mannopyranosyl)- alpha-L-rhamnopyranoside (25), methyl 4-O-benzoyl-3-O-(2,3,4,6-tetra-O-benzoyl-beta-D-glucopyranosyl)- alpha-L-rhamnopyranoside (29), methyl 4-O-benzoyl-3-O-(2,3,4-tri-O-benzoyl-beta-L-fucopyranosyl)-alpha-L- rhamnopyranoside (35), and methyl 4-O-benzyl-2-O-(2,3,4-tri-O-benzoyl-beta-L-fucopyranosyl)- alpha-L-rhamnopyranoside (59). In the syntheses of compounds 7-9, the alpha-L-fucopyranosyl residues are introduced stereoselectively, using 2,3,4-tri-O-benzoyl-alpha-L-fucopyranosyl bromide (17) and ethyl 2,3,4-tri-O-acetyl-1-thio-beta-L-fucopyranoside (47) as glycosyl donors.
authors.affiliation: N. D. Zelinsky Institute of Organic Chemistry, Academy of Sciences of the U.S.S.R., Moscow.
authors.forename: N E
authors.initials: NE
authors.lastname: Nifant'ev
authors.forename: G M
authors.initials: GM
authors.lastname: Lipkind
authors.forename: A S
authors.initials: AS
authors.lastname: Shashkov
authors.forename: N K
authors.initials: NK
authors.lastname: Kochetkov
mesh_terms: D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D006031:Glycosylation; D007202:Indicators and Reagents; D008745:Methylation; D008961:Models, Structural; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000138:chemical synthesis*; D012210:Rhamnose; D013329:Structure-Activity Relationship
chemical_list: D007202:Indicators and Reagents; D009844:Oligosaccharides; D012210:Rhamnose