In the course of developing a versatile synthetic route to natural products containing more than one five-membered carbocyclic ring (polyquinanes) we needed a general route to cyclopentadienes substituted with functionalized alkenyl chains. These compounds can serve as precursors for intramolecular Diels-Alder reacti0ns. l Two complementary routes to substituted cyclopentadienea may be envisioned (eq 1). Route A represents the well- ...
