Yamashita M, Okuyama K, Kawasaki I, Nakamura S, Nagamine R, Tsujita T, Ohta S
Kyoto Pharmaceutical University, Japan.
Chem Pharm Bull (Tokyo). 2000 Nov;48(11):1799-802. doi: 10.1248/cpb.48.1799.
Alkylidenemalonates were readily dimerized in the presence of SmI2 to give 2,3-disubstituted 1,1,4,4-butanetetracarboxylates as mixtures of meso and racemic isomers in moderate to good yields. The structure of the less polar isomer of tetraethyl 2,3-diphenyl-1,1,4,4-butanetetracarboxylate was determined by X-ray crystallographic analysis to be the meso form. Characteristic 1H-NMR behavior of the meso and racemic isomers is also discussed.
在二碘化钐存在下，亚烷基丙二酸酯很容易二聚，生成2,3 - 二取代的1,1,4,4 - 丁烷四羧酸酯，以中等至良好的产率得到内消旋体和外消旋体异构体的混合物。通过X射线晶体学分析确定了2,3 - 二苯基 - 1,1,4,4 - 丁烷四羧酸四乙酯的极性较小的异构体的结构为内消旋体形式。还讨论了内消旋体和外消旋体异构体的特征性1H - NMR行为。
