Synthesis of Angularly Fused Carbocycles via Tandem Radical Cyclization of α‐Carbonyl Radicals

An α‐carbonyl radical cyclization approach towards the synthesis of angularly fused tricyclic systems is described. On reduction with tributyltin hydride, bromo ketones yield a α‐carbonyl radical that undergoes successive 5‐exo‐dig/trig cyclizations, resulting in two or four contiguous stereocenters. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)