Triquinanes: A “One-Pot” IMDA-Tandem Metathesis Cascade Strategy: Ring-Closing Metathesis (RCM) Dominates Norbornene ROM!

A general route to linear triquinanes including a formal synthesis of (±)-Δ9(12)-capnellene is described. This cascade strategy combines an intramolecular Diels−Alder reaction tandem metathesis protocol to generate the linear cis-anti-cis-tricyclo[6.3.0.02,6]undecane skeleton directly. Significantly, the ring-closing−ring-opening−cross-metathesis (RCM−ROM−CM) sequence with our norbornene adducts is the only observed mechanism.