A short, scalable synthesis of the carbocyclic core of the anti-angiogenic cortistatins from (+)-estrone by B-ring expansion.

A rapid and scalable synthesis of the carbocyclic core of the potent antiangiogenic natural products, the cortistatins, is presented starting from readily available (+)-estrone. Key steps include a regio- and stereoselective benzylic cyanation and a Demjanov rearrangement.