Gold(I)-Catalyzed Polycyclization of Linear Dienediynes to Seven-Membered Ring-Containing Polycycles via Tandem Cyclopropanation/Cope Rearrangement/C–H Activation

A novel gold(I)-catalyzed polycyclization of easily prepared linear dienediynes has been developed for the construction of fused 5,7,6-tricyclic ring systems in one step with high diastereocontrol. The polycyclization, a formal [4 + 3]/C-H activation reaction, takes place through gold(I)-catalyzed intramolecular cyclopropanation of diene with diyne, Cope rearrangement of cis-alkenylalkynylcyclopropane, aliphatic C-H activation via a seven-membered-ring allene intermediate, and [1,2]-H and -G (H or OAc) shifts.