Cyclization into Hydrindanes Using Samarium Diiodide: Stereochemical Features Depending on the Protecting Group

: Monocyclic compounds bearing ketone and enone moieties in the same molecule can be cyclized to bicyclic compounds initiated by samarium diiodide. The stereochemistry of the products depended on the reaction conditions and also the protecting group of the hydroxy group existed in the molecule. A cyclization mechanism-is discussed.