Three synthetic routes towards a novel estrogen receptor ligand template based on a rigid bicyclo-[3.3.1]-nonene core have been investigated. The successful route employs Diels–Alder ring formation followed by trans-annular cyclization through an enolate intermediate. The prototype compound 3 exhibits potent binding at the ERβ receptor with promising selectivity against ERα, and is an agonist in MCF-7 cells. ... Subsequently, we observed that ether Figure 1 ...
