The efficient enantioselective synthesis of dihydropyrans via organocatalytic Michael addition reactions
作者:Zhiqiang Niu、Xinwei He、Yongjia Shang
DOI:10.1016/j.tetasy.2014.04.014
日期:2014.5
An asymmetric Michaeladdition of α-cyanoketones to α,β-unsaturated aldehydes to form chiral dihydropyrans catalyzed by l-diphenylprolinol trimethylsilyl ether is presented. A series of 3,4-dihydropyrans were obtained in excellent yields (up to 91%) and enantioselectivities (up to 98% ee). A plausible mechanism for this process is proposed.