The mechanism of oxidation of acetals by ozone. I. Stoichiometry, order of the reaction, solvent effects, and substituent effects

Abstract

A systematic investigation of the reaction between ozone and acetals to form acetal hydrotrioxides A has been undertaken. The stoichiometry of the reaction has been shown to be 1:1 in each reactant and the order of the reaction was also one in each reactant. Substituent effects measured in a variety of systems and under several conditions of temperature and solvent were found to be small (ρ = −1.10 to −1.58). Solvent polarity was also found to have little effect on the rate of the reaction. Mechanistically, these facts are interpreted in terms of a 1,3-dipolar insertion of ozone into the C—H bond of the acetal function.