Abstract The known 2,3,4,6-tetra-O-benzoyl-β-D-glucopyranosyl-(13)-[2,3,4,6-tetra-O-benzoyl-β-D- glucopyrano-syl-(16)]-2,4-di-O-acetyl-β-D-glucopyranosyl-(13)-2,4,6-tri-O-acetyl-α-D-glucopyranosyl- trichloroacetimidate (2) was chosen as glycosyl donor to couple with allyl 4,6-O-benzylidene-2-O-benzoyl- α-D-glucopyran-oside (4) to afford β-(1→3) linked pentasaccharide 5 in a stereo-specific manner. After removal of 4,6-O-benzylidene of 5, followed by coupling with 2,3,4,6-tetra-O-benzoyl-α-D-glucopyranosyl trichloroacetimidate (7), the blocked gluco-hexasaccharide (8) was regio- and stereo-specifically obtained. Deprotection of 8 provided the target sugar 9. Thus, a new method for the preparation of this kind of compounds was developed.

Key words: Schmidt reagent, synthesis, gluco-hexasaccharide, lentinan polysaccharide