Asymmetric Synthesis of the Tricyclic Core of Ingenane Diterpenoids via a Photocatalytic de Mayo Fragmentation Strategy

We report an asymmetric entry into the tricyclic framework of ingenane diterpenoids. The strategy features an intramolecular acyl radical Michael addition to construct the 5/5-fused system and a photocatalytic de Mayo fragmentation strategy to assemble the strained bicyclo[4.4.1]undecane core. This intermediate serves as a valuable scaffold for the synthesis of ingenane diterpenoids and their analogs.