Photochemical Reaction of Benzene-1,2,4,5-tetracarbonitrile with the Ketals of Cyclic and Bicyclic Ketones

Article abstract of DOI:10.1021/jo00084a021

The radical cations of the ethylene ketals of some cyclic and bicyclic ketones are generated by single electron transfer to excited benzene-1,2,4,5-tetracarbonitrile (TCB).Their fragmentation yields 1,5- and 1,6-distonic radical cations, which add to TCB(-.) to give <ω-<(2-hydroxyethoxy)carbonyl>alkyl>benzenetricarbonitriles.The reduction of the radical center occurs only to a small extent, and is enhanced in the presence of dodecylmercaptan, in the case of hindered radicals.The reaction of the camphor ethylene ketal (both alkylation of TCB and reduction) occurs with total diastereoselectivity at the reacting radical center.