ORGN 462

"The enantioselective synthesis of syn-beta-hydroxy-alpha-amino acids via direct aldol reactions of aldehydes with a glycinate Schiff base occurs in the presence of a phase-transfer catalyst under homogenous conditions. A survey of Cinchona alkaloid derived catalysts revealed that the trifluorobenzyl-substituted chiral ammonium salt reported by Park and Jew provided the highest levels of enantioselectivity. Although the syn:anti selectivity is negligible, the syn isomer is obtained in moderate to high ee. Our efforts to increase the diastereo- and enantioselectivity of this reaction with new catalysts will also be presented.