Hydrogen Abstraction by Ketones Type Cleavage

INTRAMOLECULAR HYDROGEN ABSTRACTION BY KETONES (TYPE II CLEAVAGE) 

With compounds containing C—H bonds y to the carbonyl moiety, one often observes intramolecular hydrogen abstraction, in contrast to the in-termolecular hydrogen abstraction by aryl ketones discussed earlier in this 

A lower molecular weight methyl ketone and an olefin are isolated as products of this reaction. That the enol is formed as a primary product which rearranges to the ketone follows from its detection in the IR spectrum of gaseous 2-pentanone upon photolysis. ° In addition to the ketone and olefinic products, one usually obtains varying amounts of cyclobutanols. 

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