Intermediates for the Synthesis of 4-Substituted Proline Derivatives

Abstract

A chemoenzymatic synthesis of a series of 2-hydroxy-5-nitro-4-substituted esters is described that uses two biotransformations in a single-pot process in which a kinetic resolution/reduction occurs. The products are valuable intermediates for the preparation of 4-substituted prolines and 5-substituted 3-hydroxypiperidinones as illustrated by the preparation of (2R,4R)-4-methylproline and (3S,5R)-3-hydroxy-5-methylpiperidinone.