Lewis Acid-Promoted Baylis-Hillman-Type Reaction of α,β-Unsaturated Ethyl Thioester with Aldehydes Without the Use of a Lewis Base.

The Baylis-Hillman-type reaction of alpha,Beta-ethyl thioacrylate with aldehydes has been achieved using diethylaluminium iodide as the promoter without the direct use of any Lewis bases. The reaction provides an effective access to various alpha-methylene-Beta-hydroxy thioesters.