Stereoselective synthesis ofvic-halohydrins and an unusual Knoevenagel product from an organocatalyzed aldol reaction：A non-enamine mode

摘要

Stereoselective synthesis by an aldol reaction between chloroacetone and aldehyde was studied using a synthesized chiral organocatalyst and triethylamine. The reaction gave α-chloro-β-hydroxy ketones in excellent yield with highantiselectivity and enantioselectivity. The chiral organocatalyst was also used in the Knoevenagel reaction, which gave α-cyano-β-hydroxy ketones at a low tem-perature and the usual Knoevenagel product at a high temperature. Both products were obtained in good to moderate yield with goodanti selectivity in the case of α-cyano-β-hydroxy ketone deriva-tives.