摘要:
Stereoselective beta-elimination in alpha,alpha-dichloro-beta-hydroxyesters 2 was achieved by using samarium diiodide, yielding (Z)-alpha-chloro-alpha, beta-unsaturated esters 1. The starting compounds 2 were easily prepared by reaction of the lithium enolate of ethyl dichloroacetate with different aldehydes at -78 degreesC. A mechanism to explain this process is proposed. (C) 2004 Elsevier Ltd. All rights reserved.