A hypervalent iodine-induced double annulation enables a concise synthesis of the pentacyclic core structure of the cortistatins

"Chemical Equation Presented" A stereocontrolled synthesis of a complex pentacycle embodying the molecular architecture of the cortistatin class of natural products was achieved from the (+)-Hajos-Parrish ketone. The cornerstone of our approach Is a hypervalent iodine induced tandem intramolecular oxidative dearomatization and nitrile oxide cycloaddition. The manner In which these ring formations were orchestrated has yielded a rather concise strategy for synthesis.