Regioselective acetylation of carbohydrates and diols catalyzed by tetramethyl-ammonium hydroxide in water

Abstract

A novel method for an efficient regioselective acetylation of carbohydrates and diols in aqueous solution is described. Treatment of substrates with 1-acetylimidazole, and tetramethyl-ammonium hydroxide (TMAH) in water under mild conditions gave highly regioselective acetylation for primary hydroxyl groups. This discovery provides an eco-friendly way for selective acetylation of non-protected glycosides and diols in water, avoiding the use of toxic organic solvents and the necessity of pre-protection of secondary hydroxyl groups.