We have developed a stereoselective synthesis of spirocylic frameworks, such as spiro[4.5]decanes or spirocyclic oxindoles, based on Claisen rearrangement in alkenyldihydropyran systems. The present Claisen rearrangement of bicyclic or tricyclic dihydropyrans, derived from easily available alcohols, is shown to afford the corresponding spirocyclic compounds in excellent yields and extremely high diastereoselectivities in all cases.
