Asymmetric Hydrolysis of Prochiral Diesters with Pig Liver Esterase. Preparation of Optically Active Intermediates for the Synthesis of ( + )-Biotin and (+)-α-Methyl-3, 4-dihydroxyphenylalanine

Abstract

With pig liver esterase, 1, 3-dibenzyl-4, 5-cis-bis(alkyloxycarbonyl)-2-oxoimidazolidine (1) was asymmetrically hydrolyzed to (4S, 5R)-l, 3-dibenzyl-5-alkyloxycarbonyl-2-oxoimidazolidine-4-carboxylic acid (2). This acid 2 was reduced with lithium borohydride to (4S, 5R)-l, 3-dibenzyl-5-hydroxymethyl-2-oxoimidazolidine-4-carboxylic acid lactone (3), which is known to be converted to ( + )-biotin (4). With the same esterase, diethyl 3, 4-dimethoxyphenylmethyl-(methyl)malonate (5) was asymmetrically hydrolyzed to (R)-ethyl hydrogen 3, 4-dimethoxy-phenylmethyl(methyl)malonate (6), which can be converted to (S)-α-methyl-3, 4-dihydroxyphenyl-alanine(L-a-methyldopa) (9).