Benzyne Insertion onto β-Keto Esters of Polycyclic Natural Products: Synthesis of Benzo Octacyclo Scaffolds.

Benzyne insertion to build the privileged scaffold of a [6.8.6]-tricyclic framework on polycyclic and sp3-rich natural products has been developed. The formation of the [6.8.6]-tricyclic ring system is solvent dependent.