Suitably protected derivatives of 1-deoxynojirimycin (1, 5-dideoxy-1, 5-imino-d-glucitol, DNJ) and its d-galacto analog were coupled with 2-thioglycosides of N-acetylneuraminic acid. The resulting disaccharides were converted into a variety of α-sialyl-(2→ 6)-and α-sialyl-(2→ 3)- DNJ derivatives, including the cyclic lactams 6-O-(5-acetamido-3, 5-dideoxy-d-glycero-α-d- galacto-2-nonulopyranosylono-1′, 5-lactam)-1, 5-dideoxy-1, 5-imino-d-glucitol and-d- ...