Chiral synthon obtained with pig liver esterase: introduction of chiral centers into cyclohexene skeleton.

A versatile chiral synthon, (1R,6S)-6-methoxycarbonyl-3-cyclohexene-1-carboxylic acid, was obtained by an enantioselective hydrolysis of the corresponding meso diester with pig liver esterase. This enzymatic hydrolysis can easily be carried out on a multi-hundred gram scale. The chiral monoester thus obtained can be further converted into all stereoisomers of 1-amino-2-alkoxycarbonyl-4-cyclohexene derivatives in an enantio- and stereocontrolled manner. These derivatives are considered as potential key intermediates for synthesizing a variety of biologically interesting compounds such as aminocyclitol and carbapenem antibiotics.