【摘要】 合成了衣康酸的三种烯丙酯:2-甲叉丁二酸双烯丙酯（双酯）,2-甲叉丁二酸1-烯丙酯（α-单酯）和2-甲叉丁二酸4-烯丙酯（β-单酯）。α-单酯和β-单酯的化学性质极其相似,很难用一般方法区分。我们比较了它们的红外吸收谱和 NMR 谱,发现后者比前者能更好地分析和鉴别它们。在 NMR 谱中,两种单酯的甲叉基（=CH₂）上的氢核有不同的化学位移,我们根据 NMR 谱中两者的吸收峰峰值之比,成功地测定了混合单酯中α-单酯和β-单酯的含量。研究了在强酸催化下衣康酸和丙烯醇的直接酯化和衣康酸双烯丙酯的部份酸性水介过程中各种酯含量的变化。发现在酯化和水介反应过程中,不仅是双酯和单酯的相对含量而且α-和β-单酯的相对含量也与酯化程度和水介程度有密切关系。在直接酯化过程中只得到少量的α-单酯,而主要得到β-单酯。但在双酯酸性水介过程中刚巧相反。从而找到了合成α-单酯的合适条件。更多还原

【Abstract】 Three allyl itaconates,diallyl 2-methylene butanedioate（diester）,1-allyl 2-methylene butanedioate （a-monoester）,4-allyl 2-methylene butanedioate （β-monoester）,were synthesized.The identification of α-and β-monoesters is difficult with the usual methods,since their chemical properties are quite similar.On comparing their IR and NMR spectra,we found that the latter is the better method for their analysis and identification.The relative content of α-monoester and β-monoester in their mixture was determined according to the ratio between the areas of their absorption peaks,since the chemical shifts of protons of the methylene group （=CH₂） present in both monoesters are different in their NMR spectra. The changes of the content of various esters in the processes both of direct esterification of itaconic acid with allyl alcohol and of the partial hydrolysis of diallyl itaconate were studied under the catalytic action of a strong acid. Our study indicates that not only the relative content of the diester and monoesters,but also that of the α-and β-monoesters is highly dependent on the degree of esterification and hydrolysis respectively.β-Monoester is obta- ined as the main product,together with a small amount of α-monoester,under the process of direct esterification,on the contrary,α-monoester is the main product in the acidic hydrolysis of the diester.Thus,the proper conditions for the synthesis of α-monoester were found.更多还原