Regioselective synthesis of 3′-O-caproyl-floxuridine catalyzed by Pseudomonas cepacia lipase

3′-O-Caproyl-floxuridine was prepared successfully through an enzymatic approach. Among the seven commercially available lipases tested, Pseudomonas cepacia lipase displayed the highest activity and regioselectivity towards the acylation of 3′-hydroxyl of floxuridine. Effects of various parameters on the acylation reaction catalyzed by P. cepacia lipase were investigated systematically. The best reaction medium was found to be acetone or acetonitrile. The optimal enzyme dosage, molar ratio of vinyl caproate to floxuridine, and reaction temperature were 40 U, 7.5, and 35 °C, respectively. Under the optimal conditions, a substrate conversion of >99% and a regioselectivity of 93.5% could be achieved after a reaction time of 4 h. The half life of P. cepacia lipase was less than 4 batches with acetone or acetonitrile as the solvent.