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 (+/-)-Delta(9(12))-capnellene is described. This cascade strategy combines an intramolecular Diels-Alder reaction tandem metathesis protocol to generate the linear cis-anti-cis-tricyclo[6.3.0.0(2,6)]undecane skeleton directly. Significantly, the ring-closing-ring-opening-cross-metathesis (RCM-ROM-CM) sequence with our norbornene adducts is the only observed mechanism.