Heterocyclic polyfluoro-compounds. Part 29. 2 : 1 Adducts by photochemical addition of cycloalkenes to pentafluoropyridine

Abstract

The cyclo-alkenes, cyclo-pentene, -hexene, and cis-octene, each add photochemically to pentafluoropyridine to yield pairs of 2 : 1 adducts by [2 + 2] addition at C-3 and -4 and [4 + 2] addition at C-2 and -5 of pentafluoropyridine. Their stereochemistry is discussed on the basis of their physical data, and it is suggested that endo-addition of cyclo-pentene and -octene, and exo-addition of cyclohexene, is favoured for [2 + 2] addition.