By using trichloroacetyl, trichloroacetimidate group and ethylthio as the protection system and through five steps, protected β-(1→3)-2-amino-2-deoxydiglucose 7 was synthesized from β-tetra-O-acetyl-glucosylamine hydrochloride (1). β-(1→3)-2-amino-2-deoxydiglucose acceptor 8 was also produced by two steps. Finally protected β-(1→3)-2-amino-2-deoxytriglucose 10 was obtained through eight steps with the tolal yield of 27%. These compounds are all new ones. Using this protection system, amino- oligosaccharides can be selectively synthesized with high yield.

Key words: glucosylamine hydrochloride, trichloroacetyl chloride, trichloroacetimidate, ethanethiol, 2-amino-2-deoxyl-triglucose