Lipase-catalyzed synthesis of methyl 6-O-poly(ε-caprolactone)glycopyranosides

An enzymatic approach to combine ring-opening polymerization of epsilon-caprolactone and regioselective acylation of methyl glycopyranosides has been investigated. Candida antarctica lipase B (Novozym 435) catalyzed the regiospecific acylation of methyl galacto-and glucopyranoside and the ring-opening polymerization of epsilon-caprolactone to give methyl 6-O-poly(epsilon-caprolactone)glucopyranosides. The synthetic strategy led to the synthesis of methyl 6-O-poly(epsilon-caprolactone)-beta-D-glucopyranoside with a M-w of 3750 and a polydispersity of 1.3. The best results were obtained by drying the system and carrying out the polymerization at 60 degrees C in bulk, without solvent. The overall conversion from methyl beta-D-glucopyranoside was 80%.