Radical Cyclization has been now variously applied as a useful method to the preparations of heterocyclic and carbocyclic compounds.'In view of efficient regioselectivity and rate of intramolecular radical addition, the reaction to give five-membered heterocyclic structures via analogues of 5-hexenyl radicals, which contain an allylic heteroatom such as oxygen or nitrogen in the chain, is often empl~ yed~~~(eq 1). Our continuous investigations on n
