Asymmetric Dehydration of beta-Styryl-beta-hydroxy Esters and Application to the Synthesis of a Neoflavonoid

摘要

Non-enzymatic kinetic resolution of racemic alcohols with a chiral catalyst is presently an area of great importance in organic chemistry.1 We have previously reported the first example for the asymmetric dehydration of beta-hydroxy esters via kinetic resolution using D-Phg-L-Pro-derived chiral ligand 1 as shown in Scheme l.The effective kinetic resolution of beta-hydroxy esters prompted us to investigate the asymmetric dehydration of beta-styryl-beta-hydroxy esters in more detail.Herein we describe our recent progress to optimize reaction conditions and to extend the scope of the methodology to various beta-styryl substituents.Also,application of this methodology to the preparation of an enantioenriched neoflavonoid is presented.