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. The resulting naphthyl radical undergoes the expected abstraction of a hydrogen atom from a second hydrogen atom donor molecule. Surprisingly, significant amounts of radical–radical recombination between the hydrogen donor radical product and the naphthyl radical were also observed for several donors. Further, in some cases, the hydrogen donor radical products also rapidly add to the uncyclized 1,2-diethynylbenzene.