Noncatalytic selective 6-O-acetylation of methyl 2,3-di-O-benzoyl-α-d-glucopyranoside with acetic acid and acetic anhydride

Abstract

Noncatalytic acetylation of methyl 2,3-di-O-benzoyl-α-D-glucopyranoside with acetic acid or acetic anhydride proceeds regioselectively at the primary hydroxyl group and aff ords methyl 6-O-acetyl-2,3-di-O-benzoyl-α-D-glucopyranoside in good yield. The possibility of 6-O-acetylation should be taken into account when removing a 4,6-O-benzylidene protecting group with aqueous acetic acid at elevated temperature.