Practical Configuration Analysis for Natural Products.

发展了一种基于碳-质子自旋耦合常数和质子间自旋耦合常数的非环有机化合物相对构型的解析方法。该方法适用于以2，3-或2，4-二取代烷烃为代表的结构单元，其中取代基为二羟基或甲基/羟基。这些方法的基本理论是，在非环系统中，相邻不对称中心的构象由交错的旋转体表示，并且它们的相对立体化学可以用这些耦合常数来确定，因为结合使用这些值可以从三和红三环构型的六种可能的旋转体中识别出主要的交错旋转体(S)。对模型化合物和天然化合物的详细构象分析表明，该方法对于非环立体化学中心的归属是可行的。

A method for elucidating the relative configuration of acyclic organic compounds was developed on the basis of carbon-proton spin-coupling constants and interproton spin-coupling constants. This method was developed for structural units represented by 2,3-or 2,4-disubstituted alkanes, where substituents were either dihydroxyl or methyl/hydroxyl groups. The basic theory of the methods is that, in acyclic systems, the conformation of adjacent asymmetric centers is represented by staggered rotamers, and their relative stereochemistry can be determined using these coupling constants because the combined use of the values enables the identification of the predominant staggered rotamer (s) out of the six possible ones derived from threo-and erythro-configuration. Detail conformational analysis for model and natural compounds, including maitotoxin, amphidinols and aflastatins, revealed that the method is practical for assignment of acyclic stereochemical centers.