Cyclohexene and Cyclooctene Epoxidation with Aqueous Hydrogen Peroxide using Transition Metal-Free Sol-Gel Alumina as Catalyst

It is shown that sol-gel alumina calcined at 400 0C is a very efficient catalyst for the epoxidation of cyclohexene and cyclooctene with aqueous 70 wt % hydrogen peroxide. The overall yield per g of catalyst was 0.28 mol of cyclohexene oxide in 5 cycles of 450 min each and 0.43 mol of cyclooctene oxide in 4 cycles of 750 min each. The selectivity for the epoxides was always better than 99%. However, the catalyst deactives slowly, which we believe is caused by a non-radical decomposition of hydrogen peroxide