Studies on Amino Sugars. II. Preparation of N-[L-α(and β)-Aspartyl]-2-acetamido-2-deoxy-β-D-glucosylamine and N-(L-γ-Glutamyl)-2-acetamido-2-deoxy-β-D-glucosylamine
N-(L-[beta]-Aspartyl)-2-acetamido-2-deoxy-[beta]-D-glucosylamine has been prepared by the condensation of N-benzyloxycarbonyl-L-aspartic acid a-benzyl ester with-O-acetyl-B-D-glucosylamine in the presence of dicyclohexylcarbodiimide followed by hydrogenolysis and de-O-acetyla-tion on the resulting 1-([alpha]-benzyl N-benzyloxycarbonyl-L-[beta]-asparta-mido)-2-acetamido-l,2-dideoxy-3,4,6-tri-O-acetyl-[beta]-D-glucose to remove the protecting groups. N-(L-[alpha]-Aspartyl)-2-acetamido-2-deoxy-[beta]-D-glucosylamine and N-(L-[gamma]-glutamyl)-2-acetamido-2-deoxy-[beta]-D-glucosylamine have been prepared by the same method as for [beta]-aspartyl-glycopeptide.