Proline-[[beta].sup.3]-amino-ester dipeptides as efficient catalysts for enantioselective direct aldol reaction in aqueous medium

Dipeptides obtained from L-proline and [[beta].sup.3]-L-amino acids which have ability to catalyze enantioselective direct aldol reaction in aqueous medium, leading to significant anti:syn diastereomeric ratios and enantiomeric excesses is reported. Both diastereo- and enantioselectivity of the catalyst could be improved by the simple introduction of a polar substituent at the C-2 position of the [[beta].sup.3]-L-amino acid.