Synthesis of optically active α-benzyl paraconic acids and their esters and assignment of their absolute configuration
作者:Federico Berti、Cristina Forzato、Giada Furlan、Patrizia Nitti、Giuliana Pitacco、Ennio Valentin、Ennio Zangrando
DOI:10.1016/j.tetasy.2009.01.027
日期:2009.2
their ethyl esters were synthesized with high enantiomeric excess by hydrolysis of the corresponding diastereomeric lactonic esters using α-chymotrypsin. Thus, at low conversion values, cis- and trans-4-benzyl-5-oxo-3-tetrahydrofurancarboxylic acids were separately isolated with 99% ee and 92% ee, respectively. Both ethyl ester diastereomers were also obtained in enantiopure form. The absolute configuration
该顺式-和反式-4- benzylparaconic酸和它们的乙酯以高对映体过量通过使用α胰凝乳蛋白酶的非对映体相应的内酯的酯的水解合成。因此,在低转化率下,分别用99%ee和92%ee分离出顺式和反式-4-苄基-5-氧代-3-四氢呋喃羧酸。两种乙酯非对映异构体也都以对映纯形式获得。所述的绝对构型反式-lactonic酸通过分配1次及其酯衍生物的1 H NMR分析与1-(9-蒽基)-2,2,2-三氟乙醇两种对映体,而所述的顺通过结晶衍生物的X射线分析确定-内酯酸。还报告了所得产物的圆二色性曲线。