The construction of cyclic systems through the intramolecular addition of carbon centered free radicals to carbon-arbon multiple bonds is well documented.'A convenient method for the sitespecific generation of carbon-centered free radicals involves the chemospecific homolysis of a C-halogen, CS, or C-Se bond by trialkyltin radicals generated from the corresponding tin hydrides2 The tin hydride induced free radical cyclizations are not ...