Preparation of tetrahydrofuran, gamma-lactone, chromanol and pyrrolidine systems by sequential 5-exo-digonal radical cyclization, 1,5-hydrogen transfer from silicon, and 5-endo-trigonal cyclization

Sequential 5-exo-digonal radical closure, intramolecular 1,5-hydrogen transfer from silicon to carbon, and 5-endo-trigonal closure of the resulting silicon-centred radicals are used to make five- and six-membered heterocycles containing oxygen or nitrogen.