Reactivity of strained olefins 1-3, 41, and 44 toward spontaneous oxygenation has been evaluated. Anglestrained olefins 1, 32, and 35 react spontaneously with ground-state triplet oxygen, at room temperature, to yield quantitatively, not copolymers or hydroperoxides, but epoxides and diketones in approximately a 2: l ratio. The autoxidation of 1 is carried out with various solvents, inhibitors, initiators, and in the presence of 2 and 1, 2- ...