No abstract

Benzaldehyde and ketones undergo no net elementary reaction with superoxide ion (O2"™•) in inert solvents such as pyridine, toluene, and benzene. Esters, however, are hydrolyzed via an initial reversible nucleophilic addition of O2-• to the carbonyl carbon followed by loss of alkoxide from the tetrahedral intermediate (rather than its reduction). This pathway is strongly supported by the relative second-order rate constants for the reaction of O2""• in pyridine with ethyl acetate (1) and phenyl acetate (104) together with results earlier reported in the literature. For the ketones and benzaldehyde, reversible initial addition of O2-• to the carbonyl must occur as well, but the absence of a viable leaving group precludes a net reaction. The decomposition products of C>2~• are highly reactive with benzaldehyde, apparently through a base-catalyzed process. These alkaline decomposition products also are reactive toward acetonitrile. The products and mechanisms for the reactions of O2-• and its decomposition products in these systems are discussed.

No abstract

No abstract

No abstract