氢氧化钠催化dl-薄荷醇异构化的研究

研究了以氢氧化钠为催化剂的dl-薄荷醇异构化反应,在220℃下达到平衡时的反应液组成 为dl-薄荷醇51％～67％,新薄荷醇20％～24％,异薄荷醇11％～13％,新异薄荷醇1．7％～2．0％、 薄荷酮10％～15％,常压蒸馏后获得的蒸馏液组成为dl-薄荷醇42％～50％,新薄荷醇25％-28％, 异薄荷醇10％～11％,新异薄荷醇2．1％～2．3％,薄荷酮14％-20％．用NaBH4对蒸馏液进行还原, 减压蒸馏后得到dl-薄荷醇51％-52％,新薄荷醇30％～32％,异薄荷醇9％～11％,新异薄荷醇 4％～8％组成的异构化产品．

Epimerization of dl-menthol with sodium hydroxide as catalyst

This paper studies on the epimerization of dl - menthol. The composition of the epim-erization reaction mixture when the equilibrium state attained was 51%-67% dl - menthol, 20% - 24% neomenthol, 11% - 13% isomenthol, 1.7% -2.0% neoisomenthol and 10% -15% menthone with sodium hydroxide as catalyst at 220. The components of the distillate was 42% - 50% dl - menthol,25% - 28% neomenthol, 10% - 11% isomenthol, 2.1% - 2.3% neoisomenthol and 14% -20% menthone. The distillate treated with NaBH4 was fractionated under reduced pressure to afford an epimer mixture constituted by 51%-52% dl - menthol,30% -32% neomenthol,9% - 11% isomenthol and 4% - 8% neoisomenthol.