To efficiently synthesize the subject compound on a large scale by reacting N-acetylaminodeoxytri-O-acetylglucopyranosyl chloride with a glycosyl acceptor in a solvent in the presence of both zinc chloride and a specific co- catalyst.

This compound is obtained by reacting N-acetyl-2-amino-2- deoxy-3,4,6-tri-O-acetyl-α-D-glucopyranosyl chloride with a glycosyl acceptor, in the presence of both zinc chloride and 4,4'-dimethoxytriphenylmethyl halide as a co-catalyst at the molar ratio of 1:1, in a solvent (e.g. dichloromethane).