Synthesis of enantiomerically pure α-amino acids via chemo- and diastereoselective alkylation of (5 S)-5-phenyl-5,6-dihydro-2 H-1,4-oxazin-2-one

Abstract

(5 S)-5-Phenyl-5,6-dihydro-2 H-1,4-oxazin-2-one 2 undergoes lewis acidmediated chemo- and diastereoselective nucleophilic addition of Grignard reagents to furnish adducts 3 which can be dismantled to allow ready access to enantiomerically pure ( S)- α-amino acids 4.