Cyclobutanone, unimolecular reaction

The first of these reactions is similar to the thermal decomposition of cyclobutanone which is believed to be a homogenous, unimolecular process (14). Both (25) and (26) which resemble similar processes in cyclopentanone and cyclohexanone have been postulated to proceed via a diradical intermediate of the formula XI (3,5). The formation of ethylene... 

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