Abstract An enantioselective total synthesis of the muscarinic inhibitor (-)-TAN1251A has been achieved. An alkylidene 1, 5-CH insertion reaction was used as a key step to produce a [5, 5]-spirocyclic intermediate, which was transformed into the [6, 5]-spirocyclic core of the natural product via an oxidative cleavage/aldol condensation sequence. The synthesis of the natural product was then completed using standard procedures.
