Practical Configuration Analysis for Natural Products.

提出了一种基于碳-质子自旋耦合常数和质子间自旋耦合常数的非环状有机化合物相对构型的解析方法。该方法是针对由2，3-或2，4-二取代烷烃表示的结构单元开发的，其中取代基是二羟基或甲基/羟基。该方法的基本理论是，在无环体系中，相邻不对称中心的构象由交错旋转异构体表示，并且它们的相对立体化学可以使用这些耦合常数来确定，因为这些值的组合使用使得能够从来自苏式和赤式构型的六种可能的旋转异构体中识别出占主导地位的交错旋转异构体。详细的模型和天然化合物，包括maitotoxin，amphidinols和aflastatins的构象分析，表明该方法是实用的非环状立体化学中心的分配。

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.