Kinetic resolutions and enantioselective transformations of 5-(acyloxy)pyrrolinones using Candida antarctica lipase B: Synthetic and structural aspects

Various 5-(acyloxy)pyrrolinones have been prepared in enantiomerically pure form by means of an enzymatic resolution or an asymmetric transformation. Either enantiomer is obtained using the same enzyme, Candida antarctica lip ase B, by modification of the procedure from transesterification to esterif ication. N-Acyl-5-(acyloxy)pyrrolinones 1 (R-2 = acyl) are synthesized by a pplying this method with 100% yield and >99% ee. To rationalize the observe d enantioselectivity and the substituent effects of these reactions both em pirical models and molecular modeling studies have been used, and a qualita tive agreement was found between the results from these studies and the exp erimental results.