Electronic Effects in the Reaction of Propionaldehyde Oxide with Substituted Benzaldehydes

Article abstract of DOI:10.1021/jo00021a030

The relative rates of reaction of propionaldehyde oxide with para-substituted benzaldehydes have been measured and treated with the Hammett equation.The Hammett plot indicates that electron-withdrawing substituents in the benzaldehyde increase the reaction rate and give ρ = +0.25.Electron-donating substituents in the benzaldehyde also increase the rate (ρ =-0.85).The results are interpreted as indicating the presence of two related pathways for ozonide formation.The cis/trans ratios of the ozonides produced in these reactions have been determined and also plotted against the Hammett ? constants.This plot indicates that electron-withdrawing substituents in the benzaldehyde increase the amount of cis ozonide formed in the reaction with propionaldehyde oxide.The results are interpreted in terms of current views of the mechanism of ozonolysis.