(S)tert-Butyl-N-tert-butoxycarbonylaziridine-2-carboxylate and (S)-tert-butyl-N-tert-butoxycarbonylaziridine-2-carboxamide were synthesised and found to react with copper 'catalysed' Grignard reagents to give protected alpha-amino acids in moderate to good yields. Copyright (C) 1996 Elsevier Science Ltd