Abstract

A new approach to two protected forms of (2S, 3S, 4S)-3-hydroxy-4-methylproline, a constituent of echinocandins and related oligopeptide antibiotics is reported. The method features a highly regioselective and diastereoselective reductive furylation of protected (2S, 3S)-3-methylmalimide and a chemoselective oxidative transformation of furyl to carboxyl as the key steps.

Keywords: proline, regioselectivity, addition, asymmetric synthesis, malic acid, echinocandins, furan, organometallics