Reductive Dimerization of Alkylidenemalonates Using Samarium(II) Diiodide and 1H-NMR Behavior of the Dimers, 2,3-Diaryl-1,1,4,4-butaneteracarboxylates.
作者:Masayuki YAMASHITA、Kazunori OKUYAMA、Ikuo KAWASAKI、Seikou NAKAMURA、Rumiko NAGAMINE、Takako TSUJITA、Shunsaku OHTA
DOI:10.1248/cpb.48.1799
日期:——
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
亚烷基丙二酸酯在SmI 2存在下易于二聚,以中等至良好的产率得到2,3-二取代的1,1,4,4-丁烷四羧酸酯,为内消旋和外消旋异构体的混合物。通过X射线晶体学分析确定2,3-二苯基-1,1,4,4-丁烷四甲酸四乙酯的低极性异构体的结构为内消旋形式。还讨论了内消旋和外消旋异构体的特征1H-NMR行为。