在四甲基联苯-3,3′,4,4′-四羧酸酯的催化氢化反应中,得到了四甲基二环己基-3,3′,4,4′-四羧酸酯,从中分离出了顺式异构体晶体。碱催化的异构化反应得到了反式异构体。通过单晶X射线衍射确定了所分离产物的结构,清晰地揭示了甲氧羰基团的轴向和赤道位置。通过1H和13C NMR数据以及二维COSY技术支持了溶液中的结构。
In the catalytic hydrogenation of tetramethyl biphenyl-3,3′,4,4′-tetracarboxylate, tetramethyl dicyclohexyl-3,3′,4,4′-tetracarboxylates were obtained, from which we have isolated cis isomers as crystals. The base-catalyzed isomerization afforded the trans isomers. The structure of the products isolated was determined by single-crystal x-ray diffraction, which clearly reveals the axial and equatorial positions of the methoxycarbonyl group. The structures in solution are supported by 1H and 13C NMR data, and also by two-dimensional COSY techniques.
在四甲基联苯-3,3′,4,4′-四羧酸酯的催化氢化反应中,得到了四甲基二环己基-3,3′,4,4′-四羧酸酯,从中分离出了顺式异构体晶体。碱催化的异构化反应得到了反式异构体。通过单晶X射线衍射确定了所分离产物的结构,清晰地揭示了甲氧羰基团的轴向和赤道位置。通过1H和13C NMR数据以及二维COSY技术支持了溶液中的结构。