title: Synthesis of benzyl 2-acetamido-2-deoxy-3-O-beta-D-fucopyranosyl-alpha-D-galactopyranoside and benzyl 2-acetamido-6-O-(2-acetamido-2-deoxy-beta- D-glucopyranosyl)-2-deoxy-3-O-beta-D-fucopyranosyl-alpha-D- galactopyranoside.
abstract: Condensation of benzyl 2-acetamido-4,6-O-benzylidene-2-deoxy-alpha-D- galactopyranoside with 2,3,4-tri-O-acetyl-alpha-D-fucopyranosyl bromide in 1:1 nitromethane-benzene, in the presence of powdered mercuric cyanide, afforded benzyl 2-acetamido-4,6-O-benzylidene-2-deoxy-3-O-(2,3,4-tri-O-acetyl-beta-D- fucopyranosyl)-alpha-D-galactopyranoside (3). Cleavage of the benzylidene group of 3 with hot, 60% aqueous acetic acid afforded diol 4, which, on deacetylation, furnished the disaccharide 5. Condensation of diol 4 with 2-methyl-(3,4,6-tri-O-acetyl-1,2-di-deoxy-alpha-D-glucopyrano)-[2, 1-d]-2- oxazoline in 1,2-dichloroethane afforded the trisaccharide derivative (7). Deacetylation of 7 with Amberlyst A-26 (OH-) anion-exchange resin in methanol gave the title trisaccharide (8). The structures of 5 and 8 were confirmed by 13C-n.m.r. spectroscopy.
mesh_terms: D002240:Carbohydrate Sequence; D004187:Disaccharides / Q000138:chemical synthesis*; D009682:Magnetic Resonance Spectroscopy; D009844:Oligosaccharides / Q000138:chemical synthesis*; D014312:Trisaccharides / Q000138:chemical synthesis*
chemical_list: D004187:Disaccharides; D009844:Oligosaccharides; D014312:Trisaccharides; C043176:benzyl 2-acetamido-2-deoxy-3-O-beta fucopyranosyl-alpha-galactopyranoside; C043177:benzyl 2-acetamido-6-O-(2-acetamido-2-deoxy-beta glucopyranosyl)-2-deoxy-3-O-beta fucopyranosyl-alpha galactopyranoside