화학공학소재연구정보센터
Chemistry Letters, Vol.35, No.4, 360-361, 2006
Diastereo- and enantioselective tandem Michael addition and lactonization between silyl enolates and alpha,beta-unsaturated ketones catalyzed by a chiral quaternary ammonium phenoxide
Diastereo- and enantioselective tandem Michael addition and lactonization between various silyl enolates derived from phenyl carboxylates and alpha,beta-unsaturated ketones were successfully carried out by using an efficient organic catalyst, a cinchonidine-derived chiral quaternary ammonium phenoxide. In this asymmetric tandem reaction, the corresponding trans-3,4-dihydropyran-2-ones were obtained in high yields with almost complete diastereoselectivities and good to excellent enantioselectivities.