An efficient stereoselective approach to silylated polyunsaturated γ-alkylidene butenolides

An efficient and stereoselective synthetic approach to a variety of polyunsaturated γ-alkylidene butenolides has been developed, starting from readily available silylated and polyunsaturated terminal alkynes. The palladium-catalysed tandem cross-coupling/cyclization reaction of the alkynes with the (Z)-3-iodo-2-propenoic acid leads directly to polyunsaturated (Z)-γ-alkylidene butenolides with a high degree of stereoselectivity.