2,3-二甲基-4-甲氧甲酰-2-环己烯醇的合成

Synthesis of 2,3-Dimethyl-4-carbomethoxy-2-cyclohexen-1-ol

在碱性条件下,甲基甲氧甲酰环己烯酮(1)与碘甲烷经烷基化反应生成二甲基甲氧甲酰环己烯酮(2),通过选择性还原酮羰基制得目标产物二甲基甲氧甲酰环己烯醇(3),反应的总收率约为60%。研究了攫氢剂和还原剂对2步反应的影响,结果表明,烷基化反应和酮羰基选择性还原反应的最佳攫氢剂和还原剂分别是氢化钠和氢化三叔丁氧基铝锂,在二者作用下所得烷基化产物和还原产物的收率分别为90%和67%。合成产物的结构经元素分析、UV-V is1、H NMR、IR和MS得到了表征。

Alkylation of methylcarbomethoxycyclohexenone 1 with iodomethane in a basic solution gave dimethylcarbomethoxycyclohexenone 2, which was transfered to dimethylcarbomethoxycyclohexenol 3 through the selective reduction of keto-carbonyl with a total yield of ca. 60%. The effects of hydrogen-grabbing agents and reducing agent on the two reactions were studied. The results show that：the optimum hydrogen-grabbing agent and reducing agent for the alkylation and selective reduction of keto-carbonyl are sodium hydride and lithiumaluminum tri-tetra-butoxy hydride, and the yields of the alkylation and the reduction product are 90% and 67%, respectively. Their structures were confirmed by means of elemental analysis, UV-Vis, ^1H NMR, IR, and MS spectra.