A model synthesis of the bicyclic core structure of the furanoheliangolide sesquiterpenes

A bicyclo[6.2.1]undecane structure, a model for the core structure of several biologically active furanoheliangolide sesquiterpenes, was synthesized through a retro–aldol reaction from a tricyclo[6.2.1.02,7]undecane. The required tricyclic compound was prepared by a Diels–Alder reaction followed by minor transformations.