Facile and regioselective preparation of partly O-benzylated D-glucopyranose acetates via acid-mediated simultaneous debenzylation-acetolysis.

Fully O-benzylated methyl alpha-D-glucopyranoside shows a steady order in stepwise debenzylation when it is treated with sulfuric acid in acetic anhydride. Based on the order of debenzylation, regioselective preparations of 2,3,4-tri-, 2,3-, 2,4-, 3,4-di-, and 2-O-benzyl-D-glucopyranose acetates were facilitated in greater than 80% yields. The key points of the preparative reactions were the control of the acid strength and choice of suitable substrates.