Reactions of Haloketenes with Allyl Ethers and Thioethers: A New Type of Claisen Rearrangement

Article abstract of DOI:10.1021/jo00154a023

A new reaction of dichloroketene (2) with allylic ethers, sulfides, and selenide 1 has been observed.A <3,3> sigmatropic rearrangement takes place at room temperature, leading to α,α'-dichloro-γ,δ-unsaturated esters 3.The scope of this reaction was further investigated with dibromoketene (16), difluoroketene (17), electron-deficient chloroketenes, and different allylic systems.In the course of these studies, total syntheses of two naturally occurring macrolides, phoracantholide I and phoracantholide J, were achieved.Medium-ring conformations are discussed.