The synthesis of 2-acetamido-2-deoxy-6-O-beta-D-mannopyranosyl-D-glucose

4,6-Di-O-acetyl-2,3-O-carbonyl-alpha-D-mannopyranosyl bromide was condensed with benzyl 2-acetamido-3,4-di-O-acetyl-2-deoxy-alpha-D-glucopyranoside in the presence of silver carbonate to give crystalline benzyl 2-acetamido-3,4-di-O-acetyl-2-deoxy-6-O-(4,6-di-O-acetyl-2,3-O-carbonyl-beta-D-mannopyranosyl)-alpha-D-glucopyranoside in 32% yield. Removal of the protective O-acetyl and cyclic carbonate groups gave the crystalline benzyl alpha-glycoside of the disaccharide, which was catalytically hydrogenolyzed to yield the crystalline, title compound. Proof of the anomeric configuration of the interglycosidic linkage was obtained by comparison of the physical, spectral, and chromatographic properties of the disaccharide and its derivatives with those of the previously prepared alpha-D-linked analog.