摘要:
Colyophilization of pig liver esterase with methoxypolyethylene glycol gave a catalyst, PLE/MPEG, which showed an enhanced activity in organic solvents. The PLE/MPEG catalyzed transesterification of the alcohols rac-1a-d with vinyl propionate in toluene proceeded with good to high selectivities. The addition of up to 1% of water to the reaction mixture resulted in a significant increase in enantioselectivity. Immobilization of PLE/MPEG for the batch-wise resolution was accomplished by its spontaneous adsorption on an ultrafiltration membrane. (C) 1997 Elsevier Science Ltd.