Reactivity of 1,4-didehydronaphthalene toward organic hydrogen atom donors

1,4-Didehydronaphthalene, generated by thermolysis of 1,2-diethynylbenzene, reacts with organic hydrogen atom donors via hydrogen atom abstraction. Th e resulting naphthyl radical undergoes the expected abstraction of a hydrog en atom from a second hydrogen atom donor molecule. Surprisingly, significa nt amounts of radical-radical recombination between the hydrogen donor radi cal product and the naphthyl radical were also observed for several donors. Further, in some cases, the hydrogen donor radical products also rapidly a dd to the uncyclized 1,2-diethynylbenzene. (C) 2000 Elsevier Science Ltd. A ll rights reserved.