Synthesis of mannose-containing analogues of (1 → 6)-branched (1 → 3)-glucohexaose Original Research Article

Coupling of the trisaccharide acceptor 2,4,6-tri-O-acetyl-β-d-glucopyranosyl-(1 → 3)-[2,3,4,6-tetra-O-benzoyl-β-d-glucopyranosyl-(1 → 6)]-5-O-acetyl-1,2-O-isopropylidene-α-d-glucofuranose () with the trisaccharide donor 2,3,4,6-tetra-O-benzoyl-α-d-annopyranosyl-(1 → 3)-[2,3,4,6-tetra-O-benzoyl-β-d-glucopyranosyl-(1 → 6)]-2,4-di-O-acetyl-α-d-glucopyranosyl trichloroacetimidate () gave an α-linked hexasaccharide , while coupling of with the trisaccharide donor 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl-(1 → 3)-[2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl-(1 → 6)]-2,4-di-O-acetyl-α-d-glucopyranosyl trichloroacetimidate () produced α- and β-linked hexasaccharides in a ratio of 3:2. Deprotection of , , and afforded the analogues of the immunomodulator β-d-Glcp-(1 → 3)-[β-d-Glcp-(1 → 6)]-α-d-Glcp-(1 → 3)-β-d-Glcp-(1 → 3)-[β-d-Glcp-(1 → 6)]-d-Glcp ().