A sulfoxide version of the Julia-Lythgoe olefination: A new method for thesynthesis of olefins from carbonyl compounds and sulfoxides with carbon-carbon coupling

Reaction of beta-mesyloxy (or acetoxy) sulfoxides, derived from alkyl (or a rylmethyl) phenyl sulfoxides and carbonyl compounds in two steps, with alky lmetals (n-BuLi, t-BuLi, or EtMgBr) at low temperature gave olefins in good to excellent yields. When the beta-hydroxy sulfoxides derived from arylald ehydes were treated with mesyl chloride in the presence of triethylamine, t he sulfoxides directly gave E-olefins in good yields. These reactions offer a sulfoxide version of the Julia-Lythgoe olefination. The reductive vicina l elimination was found to take place through the direct sulfoxide-metal ex change. The stereochemistry of the elimination was investigated and found t o be stereospecific; however, the stereospecificity was found to be depende nt on the substrates. (C) 2000 Elsevier Science Ltd. All rights reserved.