Radical-mediated annulation reactions. A versatile strategy for the preparation of a series of carbocycles

[GRAPHICS] A series of novel 6-endo [4 + 2] and 7-endo [5 + 2] radical-mediated annula tion reactions are described. These annulation sequences involve an intermo lecular radical addition followed by intramolecular trapping with an allylt in moiety incorporated into the radical precursor fragment. This methodolog y allows for access to functionalized 6- and 7-membered carbocycles as well as bicyclic compounds with good to excellent levels of stereocontrol.