Stereocontrolled Synthesis of an Indole Moiety of Sespendole and Stereochemical Assignment of the Side Chain

Two possible diastereomers of the indole moiety of sespendole were synthesized from 3-hydroxy-4-nitrobenzaldehyde in a highly stereoselective manner. Comparison of 1H and 13C NMR spectra of the two synthetic materials with those sespendole leads us to propose that the relative stereochemistry of the epoxyalcohol is syn.

本研究以3-羟基-4-硝基苯甲醛（3-hydroxy-4-nitrobenzaldehyde）为起始原料，采用高立体选择性合成策略，制备得到塞斯潘多（sespendole）吲哚片段（indole moiety）的两种潜在非对映异构体（diastereomers）。将两种合成产物的氢谱（¹H NMR）与碳谱（¹³C NMR）与塞斯潘多的对应谱图进行比对后，我们推定该环氧醇（epoxyalcohol）的相对立体构型为顺式（syn）。