Rh-catalyzed triple allene approach to bicyclo[4.4.0]decene derivatives and its application for the stepwise synthesis of steroid-like tetracyclic skeletons

The construction of a new type of bicyclo[4.4.0]decene products with a conjugated exocyclic diene unit was developed using Rh-catalyzed cyclization of 1,5-bisallenes in the presence of monoallenes. The steroid-like tetracyclic products could be obtained by applying an alkylation-Diels-Alder process.