Construction of dispirocyclohexanes via amine-catalyzed [2 + 2 + 2] annulations of Morita–Baylis–Hillman acetates with exocyclic alkenes

Divergent amine-catalyzed [2 + 2 + 2] annulations of Morita–Baylis–Hillman acetates with exocyclic alkenes were developed for the convergent construction of multistereogenic dispirocyclohexanes.