Enzymes in Organic Synthesis. 35. Stereoselective Pig Liver Esterase Catalyzed Hydrolyses of 3-Substituted Glutarate Diesters. Optimization of Enantiomeric Excess via Reaction Conditions Control

Article abstract of DOI:10.1021/jo00361a021

Pig liver esterase catalyzed hydrolyses of C-3-substituted dimethyl glutarates are enantiotopically selective, giving acid ester products of 17-79percent ee under normal (aqueous, pH 7, 20 deg C) hydrolysis conditions.The stereoselectivity can be increased by optimizing the reaction conditions.For example, in 20percent aqueous methanol of pH 7 at -10 deg C hydrolysis of the 3-methyl diester gives the 3-methyl acid ester of 97percent ee.The hydrolysis is pro-S selective for the diesters with small C-3 substituents and reverses to pro-R preference when C-3 is large.An active site model consistent with these data is presented.