A Concise Approach to Anthraquinone–Xanthone Heterodimers

A synthetic approach to anthraquinone–xanthone heterodimers is described. The route to the pentacyclic core features an efficient assembly of a benzocycloheptenone via a new intramolecular oxidative arylation of an enol ether and a Hauser–Kraus annulation–aldol reaction sequence to access the characteristic bicyclo[3.2.2]­nonene motif. Acremoxanthone A is synthesized in 10 steps from commercially available material to demonstrate the application of this approach.