Oxidation of Aliphatic Unsaturated Systems

A matter of much dispute has been whether the photo-oxidation of olefins to allylic hydroperoxides involves an ene-reaction or a perepoxide intermediate (see 

Brewer, R. Kayser, R. Martin, D. Feriozi, and R. A. Keller, Canad. J. Chem., 

In the past year no more evidence has been produced which strongly supports a perepoxide as an intermediate in this reaction. Jefford and Boschung121 report interesting results on the mechanism of 2 attack on olefins from a study of the methylene blue-sensitized photo-oxidation of the norbornenes 

Jefford and Boschung122 also report that norbornene (58) is not inert to singlet oxygen, as previously supposed. Photo-oxygenation of (58) in acetonitrile, 

Chung and Scott188 have claimed that sensitized photo-oxidation of the cyclodecadiene (64) leads exclusively to the hydroperoxide (65). No products of a 

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