Synthesis of O-(2-acetamido-2-deoxy-beta-D-glucopyranosyl)-(1----3)-O-beta-D- galactopyranosyl-(1----4)-2-acetamido-2-deoxy-D-glucopyranose and two related trisaccharides containing the "lacto-N-biose II" unit.
Condensation of 3-O-(2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-beta-D- glucopyranosyl)-2,4,6-tri-O-acetyl-alpha-D-galactopyranosyl bromide (1) with benzyl 2-acetamido-3,6-di-O-benzyl-2-deoxy-alpha-D-glucopyranoside in boiling benzene and in the presence of mercuric cyanide afforded a trisaccharide that was O-deacetylated to give benzyl O-(2-acetamido-2-deoxy-beta-D-glucopyranosyl)-(1----3)-O-beta-D- galactopyranosyl-(1----4)-3,6-di-O-benzyl-2-deoxy-alpha-D-glucopyranosid e, the benzyl groups of which were cleaved by catalytic hydrogenolysis to furnish the title trisaccharide. Alternatively, bromide 1 was allowed to react with 2-acetamido-1,6-anhydro-3-O-benzyl-2-deoxy-beta-D-glucopyranose in 1:1 benzene-nitromethane in the presence of mercuric cyanide, followed by O-deacetylation, column chromatography, and reacetylation to give O-(2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-beta-D- glucopyranosyl)-(1----3)-O-(2,4,6-tri-O-acetyl-beta-D-galactopyranosyl)- (1----4)-2-acetamido-1,6-anhydro-3-O-benzyl-2-deoxy-beta-D-glucopyranose . Acetolysis, followed by catalytic hydrogenation and subsequent O-deacetylation furnished the title trisaccharide. A similar condensation of bromide 1 with 4-nitrophenyl 2-acetamido-2-deoxy-4,6-O-(4-methoxybenzylidene)-beta-D-glucopyran oside and 2-nitrophenyl 2-acetamido-2-deoxy-4,6-O-(4-methoxybenzylidene)-alpha-D-galactopy ranoside produced two trisaccharide derivatives, the acetal groups of which were cleaved in hot, 60% aqueous acetic acid, and the resulting diol intermediates O-deacetylated to furnish the desired trisaccharides 4-nitrophenyl O-(2-acetamido-2-deoxy-beta-D- glucopyranosyl)-(1----3)-O-beta-D-galactopyranosyl)-(1----3)-2-acetamido -2- deoxy-beta-D-glucopyranoside and 2-nitrophenyl O-(2-acetamido-2-deoxy-beta-D-glucopyranosyl-(1----3)-O-beta- D-galactopyranosyl-(1----3)-2-acetamido-2-deoxy-beta-D-galactopyranoside .
Department of Gynecologic Oncology, Roswell Park Memorial Institute, New York State Department of Health, Buffalo 14263.
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Thomas
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Dubey
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Abbas
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Matta
D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D004187:Disaccharides; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D013329:Structure-Activity Relationship; D014312:Trisaccharides / Q000138:chemical synthesis*
D004187:Disaccharides; D007202:Indicators and Reagents; D014312:Trisaccharides; C040456:lacto-N-biose II