Synthesis of cyclohexanone glycol ketal catalyzed by rare earth composite solid superacid SO_4~(2-)/ZrO_2/Gd~(3+) under microwave radiation

Cyclohexanone glycol ketal was synthesized using cyclohexanone and glycol as reactants and rare earth composite solid superacid SO_4~(2-)/ZrO_2/Gd~(3+)as catalysts without solvent under microwave irradiation.The effects of reactant molar ratio,amount of catalyst,microwave irradiation power,micro- wave irradiation time on the yield of cyclohexanone glycol ketal were studied.The optimal conditions were as follows:n(cyclohexanone):n(glycol)= 1:3.0,mass ratio of catalyst to reactant 1.50 %,mi- crowave irradiation power 425 W and radiation time 10 min.Under these conditions,the yield of cyclo- hexanone glycol ketal could be reach 90.4%,indicating that rare earth composite solid superacid SO_4~(2-)/ZrO_2/Gd~(3+)is a good catalyst for the synthesis of cyclohexanone glycol ketal.