Study on Synthesis of Novel Seven-membered-ring Acetals(Ketals) over HZSM-5 Catalyst

The acetalization and ketalization of various aldehydes and ketones with 1,4-butadiol using HZSM-5 as catalyst were studied.The process is highly effective,environmentally benign,and very selective.Effects of reaction time,mole ratio of reactants and amount of catalyst on yield of acetals(ketals) were investigated.Results showed that HZSM-5 was an efficient catalyst for acetalization and ketalization with high conversion and selectivity under mild conditions.The optimum reaction conditions were molar ratio of aldehydes and ketones to 1,4-butanediol was 1∶1.5;catalyst amount was 2.5 g / 1 mol aldehydes or ketones;and reaction time was 2 h.Furthermore,the conversion was over 90 % and the selectivity was over 97 %.