Quaternary carbon construction through Piancatelli rearrangement: easy access to spirocyclopentenones

A new and efficient approach to a series of novel multifunctionalized spirocyclopentenone scaffolds through Piancatelli rearrangement was developed under metal-free conditions. This method has been successfully applied to O-, N- and C-nucleophiles with excellent yields. An efficient approach to a series of novel multifunctionalized spirocyclopentenone scaffolds through Piancatelli rearrangement under metal-free conditions.