Synthesis of the repeating units of Schizophyllan

Abstract

The tetrasaccharides β- d-Gl cp-(1→3)-β- d-Gl cp-(1→3)-[β- d-Gl cp-(1→6)]- d-Gl cp, β- d-Gl cp-(1→3)-[β- d-Gl cp-(1→6)]-β- d-Gl cp-(1→3)- d-Gl cp, and β- d-Gl cp-(1→6)-β- d-Gl cp-(1→3)-β- d-Gl cp-(1→3)- d-Gl cp, corresponding to the three possible repeating-units of Schizophyllan, have been synthesised by silver trifluoromethanesulfonate-promoted Koenigs-Knorr type condensations, using 2,4,6-tri- O-acetyl-3- O-allyl-α- d-glucopyranosyl bromide as the key intermediate.