Determination of Absolute Stereostructure of Organic Compounds by Means of X-Ray Crystallographic and Circular Dichroic Methods

用X射线晶体学和圆二色性方法测定了各种手性有机化合物的绝对立体结构。阐明了CD激子手性方法适用于含有两个或两个以上不同发色团的非简并体系，并测定了含有蒽发色团的三蝶烯体系、从海藻中分离的多拉司坦二萜的异戊醇、水稻抗稻瘟病的自我防御物质不饱和羟基脂肪酸、含有蒽发色团的三蝶烯体系、含有蒽发色团带有角保护的羟甲基的光学活性Wieland-Miescher酮类似物;致癌的苯并[e]芘衍生物;反式-2，3-二取代的螺环丙烷-1，9 '-芴衍生物; 2，2'-螺二苯并[e]茚满衍生物;来自D-亮氨酸的手性类固醇CD-环合成子。此外，我们还建立了确定绝对立体结构的CD方法， ...更多信息 许多天然产物具有扭曲的<pi>共轭电子体系.我们发现，对于确定这类化合物的绝对立体结构，用<pi>电子SCF-CI-偶极速度MO方法计算CD谱是非常有用的。例如，我们成功地确定了绝对立体结构的（+）-1，8 α-二氢-3，8-二甲基甘菊，一个不稳定的生物合成的中间体1，4-二甲基甘菊从苔分离，通过计算CD光谱使用本MO方法。通过合成合适的手性模型化合物，实验验证了理论结论。应用该方法测定了下列具有扭曲共轭电子体系的化合物的绝对立体结构<pi>：新型手性托品螺环化合物、冲绳海绵的强心活性成分卤喹啉及其衍生物、顺式和反式-4，4 '-联菲亚基的手性烯烃。X射线衍射法和圆二色谱法是互补的，通过X射线晶体学研究确定了二氢甘菊环模型化合物合成中间体的绝对立体化学，证明了两种方法的一致性。少

The absolute stereostructure of various chiral organic compounds were determined by means of X-ray crystallographic and circular dichroic methods. We clarified that the CD exciton chirality method is applicable to the non-degenerate systems containing two or more different chromophores, and determined the following biologically active natural products and synthetic chiral organic compounds: triptycene systems containing an anthracene chromophore; isoamijiol of a dolastane diterpene isolated from a seaweed; unsaturated hydroxy fatty acids, the self defensive substances in rice plant against rice blast disease; optically active Wieland-Miescher ketone analogues bearing an angular protected hydroxymethyl group; carcinogenic benzo[e]pyrene derivatives; trans-2, 3-disubstituted spirocyclopropane-1,9'-fluorene derivatives; 2,2'-spirobibenz[e]indan derivatives; a chiral steroid CD-ring synthon from D-leucine. Furthermore, we established the CD method for determining the absolute stereostructu … More re of acyclic glycols.There are many natural products having a twisted conjugated <pi> -electron system. We have found that for determination of absolute stereostructure of such compounds, the theoretical calculation of CD spectra by the <pi> -electron SCF-CI-dipole velocity MO method is very useful. For instance, we succeeded to determine the absolute stereostructure of (+)-1,8a-dihydro-3,8-dimethylazulene, a labile biosynthetic intermediate for 1,4-dimethylazulene isolated from a liverwort, by calculation of CD spectra using the present MO method. The theoretical conclusion was experimentally proved by the synthesis of suitable chiral model compounds. By applying this method, the absolute stereostructures of the following compounds having a twisted conjugated <pi> -electron system were determined: novel chiral troponoid spiro compounds; a cardiac active constituent of an Okinawan marine sponge, halenaquinol and its derivative; chiral olefins of cis- and trans-4,4'-biphenanthrylidenes. The X-ray and CD methods are complementary each other, and the absolute stereochemistry of the synthetic intermediate of the dihydroazulene model compounds was established by the X-ray crystallographic studies, proving that both of the methods are consistent with each other. Less