Cyclohexenones as Michael Acceptors in the Staunton−Weinreb Annulation: A Simple Stannane Modification for the Synthesis of Polycyclic Systems

o-Toluate anions generated via transmetalation from the corresponding tributyl stannane underwent a Michael addition−Dieckmann condensation sequence with various cyclohexenones. This protocol provides an efficient entry into complex polycyclic systems without the use of β-alkoxy enones hitherto required for the reaction.