Efficient preparation of trisubstituted alkenes using the Julia-Lythgoe olefination of ketones. On the key-role of SmI2 in the reductive elimination step.

Modification of the Julia-Lythgoe olefination reaction between ketones and primary sulfones leads to trisubstituted alkenes in good overall yields. Samarium diiodide is shown to play a crucial role in the reductive elimination step.