Dioxetanes pyrolysis

The conversion of small rings to smaller ones, without loss, is not common. 3-Chloroazetidine isomerizes reversibly to 2-chloromethylaziridine (Section 5.09.2.2.5). Flash vacuum pyrolysis can convert isoxazoles to azirines (Section 5.04.4.3). More common is the isomerization of medium-sized, i.e. five- or six-membered rings, e.g. certain succinimides (Scheme 23) (81JOC27) to azetidinediones, or bicyclic 1,2-dioxetanes to bis-oxiranes (Section 5.05.4.3.2). 

The peroxide radical can go to a product by abstraction and generate for example an acid and another radical. Commonly, acetic acid and also formic acid are formed in considerable amount during oxidative pyrolysis. The previous mechanism can probably explain the formation of these small molecules. The oxygen (singlet oxygen) may also react with the double bond forming a dioxetane intermediate ... 

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