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

X 射线晶体学和圆二向色法测定有机化合物的绝对立体结构

基本信息

批准号：
59430005
负责人：
HARADA Nobuyuki
金额：
$ 15.62万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (A)
财政年份：
1984
资助国家：
日本
起止时间：
1984 至 1986
项目状态：
已结题

项目摘要

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

通过X射线晶体学和圆形二色性方法确定各种手性有机综合作用的绝对立体结构。有机化合物：围绕海藻分离的蒽苯二苯二甲酸苯二苯二甲酸酯； 2,2'-SpiRobibenz [e] indan衍生物;为了确定学校化合物的绝对立体结构，通过<pi> - 电子SCF-CI-CI-偶极速度E对CD光谱进行了理论化，以确定（+）-1,8a-dihydro- 3,8-二甲基津的绝对立体结构，一种从肝脏中分离出的1,4-二甲基硫酸的中间体，使用E当前的MO方法，通过合成合适的手性模型来证明理论结论。这是某种方法，确定了具有扭曲的copogy <i> - 电子系统的绝对刻板。 X射线晶体学研究建立了4,4'-Biphenanthrylidens