A Recyclable Organocascade Reaction System: Stereoselective Precipitation of Optically Active cis-δ-Lactols with Quaternary Stereocenters during the Michael-Hemiacetalization Reaction
作者:Fanglin Zhang、Mohui Wei、Junfang Dong、Yirong Zhou、Dengfu Lu、Yuefa Gong、Xiangliang Yang
DOI:10.1002/adsc.201000553
日期:2010.11.22
A cascade Michael–hemiacetalization reaction between β-substituted β-nitroethanols and α,β-unsaturated aldehydes is described, which provides a convenient and efficient synthesis for cis-δ-lactols with quaternary stereocenters in moderate yields with excellent enantioselectivity. Based on the selective precipitation of cis-δ-lactols, which were isolated by filtration, the catalytic system in the filtrate
描述了β-取代的β-硝基乙醇与α,β-不饱和醛之间的级联迈克尔-半缩醛化反应,它为具有四级立体中心的顺式-δ-内酯提供了方便高效的合成方法,具有中等收率和优异的对映选择性。基于通过过滤分离出的顺式-δ-内酯的选择性沉淀,滤液中的催化体系可以直接重复使用并循环八次,而对映选择性没有任何明显的下降。