Regioselective Hydrolysis of Carbohydrate Secondary Acyl Esters By Lipases1

Abstract
Treatment of 1, 6-anhydro-2, 3, 4-tri-O-n-butanoyl-β-D-glucopyranose (3) with lipase preparations of Pseudomonas sp., Mucor miehei or Chromobacterium viscosum in aqueous media resulted in regioselective removal of the acylester at C-4 to afford 1, 6-anhydro-2, 3-di-O-n-butanoyl-β-D-glucopyranose (5). The C-2 acylester of compound 5 was efficiently removed with lipase of Candida cylindracea to give 1, 6-anhydro-3-O-n-butanoyl-β-D-glucopyranose (6). For 1, 6-anhydro-2, 3, 4-tri-O-n-butanoyl-β-D-galactopyranose (4) a different pattern of enzymatic hydrolysis was observed, indicating that the stereochemistry at C-4 is important for enzymatic hydrolysis.