The ring closure of a series of ω-(benzylseleno) alkyl radicals (1) has been studied. Thiohydroxamic esters derived from ω-(benzylseleno) alkanoic acids decompose smoothly, upon irradiation, with the loss of carbon dioxide to afford 5–and 6–membered selenium- containing rings in 78–95% yield. The thiohydroxamic ester derived from 7-(benzylseleno) heptanoic acid affords the 7-membered heterocycle, selenopane in approximately 50% ...
