and a catalytic amount of AIBN in boiling benzene caused 5-exo cyclization of allylic O-stannyl ketyl radicals generated by addition of Bu3Sn· on the amide-oxygen atoms to provide γ-lactams 2a–h after acidic workup. When enamide 1d was treated with Bu3SnH in the presence of AIBN followed by aldehydes 3a–d, sequential radicalcyclization and aldol reactions occurred to afford anti-adducts 4a–d and syn-adducts