Zinc bromide promoted addition of trimethylsilyl butenoate lithium enolates to aromatic aldimines. The corresponding P-amino acids were obtained in moderate to good yields as anti isomers. The reaction was believed to proceed via the zinc enolates. A tentative explanation of the selectivity in favour of the anti isomers was proposed. (C) 2002 Elsevier Science B.V. All rights reserved.