Epoxidation of Alkenes with Peracids
Epoxidation of Alkenes with Peracids: Substituent Effects
Relative reaction rates for the epoxidation of alkenes
The outcome of the epoxidation of a double bond is determined by the substituents; the effect of solvent polarity on the reaction rate is negligible. However, protic solvents prevent the formation of the hydrogen bond. Therefore, chlorinated hydrocarbons are mostly used. Electron-donating substituents at the C=C double bond, for example alkyl groups, increase the rate of addition of the electrophilic oxygen atom.
Since the reaction in principle is an electrophilic addition, reaction rates also increase if the peracid contains electron-withdrawing substituents.