Organocatalytic sequential α-aminoxylation and cis-Wittig olefination of aldehydes: synthesis of enantiopure γ-butenolides
作者:Dattatray A. Devalankar、Pandurang V. Chouthaiwale、Arumugam Sudalai
DOI:10.1016/j.tetasy.2012.02.004
日期:2012.2
A short route to enantiopure gamma-butenolides (up to 99% ee) has been developed from readily available starting materials. The strategy involves a sequential organocatalytic alpha-aminoxylation followed by cis-Wittig olefination of aldehydes. The utility of this protocol has been demonstrated in the asymmetric synthesis of trans-(+)-cognac lactone with high enantiomeric purity. (C) 2012 Elsevier Ltd. All rights reserved.
Asymmetric, Organocatalytic, Three-Step Synthesis of γ-Hydroxy-(<i>E</i>)-α,β-Unsaturated Sulfones and Esters
作者:Kimberly S. Petersen、Gary H. Posner
DOI:10.1021/ol8020513
日期:2008.10.16
Efficient and enantiocontrolled synthesis of gamma-hydroxy-alpha,beta-unsaturated sulfones and esters are reported through the reaction of enantioenriched alpha-selenyl aldehydes with EWG-stabilized carbanions and then a one-pot selenide oxidation, in situ epoxide formation, and final in situ epoxide opening.