Stereoselective alpha-alkylation of new chiral auxiliaries: An access to enantiomerically pure alpha- and alpha,beta-substituted beta-amino acids

New bicyclic heterocycles 5, which are potentially useful for the enantiose lective synthesis of substituted beta-amino acids, have been synthesized. A study on the alpha-alkylation of these chiral auxiliaries is presented. An optically pure beta-amino acid was obtained in excellent yield from its ma sked chiral derivative 6a.