柑青醛制备新铃兰醛最佳反应条件的探索

Study on the Best Reaction Conditions for Preparing Lyral From Myrac Aldehyde

以柑青醛为原料,经过醛基保护再水合的方法合成了新铃兰醛,通过FT-IR确认了中间体及产物的结构.考察了合成中间体-柑青醛吗啉烯胺以及继续合成新铃兰醛的反应条件.结果表明:在反应温度118℃,甲苯为溶剂,柑青醛与甲苯体积比1/3.5,85％的磷酸占柑青醛质量分数的2.0％,柑青醛与吗啉摩尔比为1/2.1,反应时间8h的条件下合成中间体,柑青醛的转化率达到最高83.5％.中间体-柑青醛吗啉烯胺在40％的硫酸水溶液中,0～5 ℃下进行水合反应,新铃兰醛产率达到最高70.6％.

Lyral,4-(4′-methyl-4′-hydroxyamyl)-△3-cyclohexenecarboxaldehyde and its structural isomer were prepared from myrac aldehyde by the method of the protecting aldehyde group and then the hydration.The structure of intermediates and products was affirmed by FT-IR.The reaction conditions for synthesizing intermediates and lyral were studied.The results show that when volume ratio of myrac aldehyde to toluene is 1/3.5,the mass percent of 85% phosphoric acid is 2.0% in the myrac aldehyde,molar ratio of myrac aldehyde to morpholine is 1/2.1,intermediates can be synthesized at 118 ℃ for 8 h by using the toluene as solvent,and the conversion of myrac aldehyde is 83.5%.The hydration reaction of the intermediates can proceed in 40% sulfuric acid solution at 0~5 ℃,and lyral yield is 70.6%.