Enantioselective synthesis of (S)-4-methyleneglutamic acid via tandem conjugate addition-elimination under phase-transfer catalytic conditions

Abstract

An efficient enantioselective synthetic method for (S)-4-methyleneglutamic acid is reported. Phase-transfer catalytic conjugate addition-elimination of the benzophenone imine of glycine tert-butyl ester in the presence of chiral Cinchona-derived catalysts give the corresponding conjugated addition products (>99% ee), which could be hydrolyzed to chiral (S)-4-methyleneglutamic acid. © 2010 Elsevier Ltd. All rights reserved.