PHOTOINDUCED REACTIONS OF 3β-ACETOXYCHOLESTA-5,7-DIENE, 3β-ACETOXYCHOLEST-5-ENE, TETRAPHENYLCYCLOPENTADIENE AND 1,1-DIPHENYLETHYLENE WITH OXYGEN IN THE PRESENCE OF PHENYLSELENYL BROMIDE

Article abstract of DOI:10.1016/S0040-4039(00)85518-5

Whereas PhSeBr under irradiation with O2 in CH2Cl2 at -78 deg C acts as a photoxygenation catalyst to convert 3β-acetoxycholesta-5,7-diene and tetraphenylcyclopentadiene into the corresponding endoperoxides, and 3β-acetoxycholest-5-ene into 3β-acetoxycholest-5-en-7-one and the corresponding alcohols, it reacts with 1,1-diphenylethylene to give mainly a bromohydrin; bromine radicals arising by photodissociation of the PhSeBr are implicated as the active intermediates.