The effect of tert-butyl alcohol and 2,3 -epoxy-2-ethylpropyl ethacrylate, the reaction products, on the epoxidation of ethylallyl ethacrylate with tert-butyl hydroperoxide was studied in the presence of molybdenum boride (Mo2B) as a catalyst. It was found that the alcohol accelerated and the epoxide and its secondary transformation product inhibited the reaction. The kinetic scheme was proposed, and the kinetic parameters of the reaction were calculated.