An efficient oxidative dearomatization-radical cyclization approach to symmetrically substituted bicyclic guttiferone natural products

摘要

Detailed in this communication is an efficient synthetic approach towards the guttiferone family of natural products. Oxidatively unraveling a para-quinone monoketal followed by consecutive 5-exo radical cyclizations provides the bicyclic core. An additional strength of this approach is a late stage asymmetric desymmetrization of an advanced symmetric intermediate. In recent years a vast number of bridged bicyclic polypreny-lated acylphloroglucinol natural products have been reported. Perhaps the most famous member of this family of natural products is hyperforin, which is one of the main chemical constituents of the commonly used natural remedy St. John's wort and has in recent years shown promise as a potential anticancer agent.