Synthesis of (Z)-α-chloro-α,β-unsaturated esters with complete stereoselectivity promoted by samarium diiodide

Article abstract of DOI:10.1016/j.tetlet.2004.04.101

Stereoselective β-elimination in α,α-dichloro-β- hydroxyesters 2 was achieved by using samarium diiodide, yielding (Z)-α-chloro-α,β-unsaturated esters 1. The starting compounds 2 were easily prepared by reaction of the lithium enolate of ethyl dichloroacetate with different aldehydes at -78°C. A mechanism to explain this process is proposed.