Efficient preparation of trisubstituted alkenes using the SmI2 modification of the Julia–Lythgoe olefination of ketones and aldehydes

High yields of di- and tri-substituted alkenes are obtained by a modification of the Julia–Lythgoe olefination reaction involving the in situ capture of intermediate β-alkoxy-sulfones by benzoyl or trimethylsilyl chloride, followed by SmI2-mediated reductive elimination. This novel protocol also provides a connective preparation of dienyl ethers, which are important partners in Diels–Alder cycloadditions.