Abstract A copper sulfate pentahydrate-catalyzed intramolecular Friedel–Crafts reaction using an oxocarbenium species derived from a furan ring as the alkylating agent was developed for the first time. By using this protocol, spirofurooxindoles 9 with multi-reactive sites were synthesized simply and concisely. In addition, selective hydrogenation of the endo-cyclic double bond and full hydrogenation of the endo and exo-cyclic double bonds ...
