作者:Bunta Watanabe、Katsunori Makino、Masaharu Mizutani、Hikaru Takaya
DOI:10.1016/j.tet.2021.132194
日期:2021.7
Calibagenin and saxosterol are cholesterol-based plant steroids isolated from Calibanus hookerii and Narthecium ossifragum, respectively. To date, the configurations of their 16- and 22-hydroxy groups have not yet been determined. In this study, all the four 16,22-stereoisomers were chemically synthesized. The 1H and 13C NMR spectra were fully assigned using 2D NMR techniques, and the structures were
Calibagenin 和 Saxosterol 是分别从Calibanus hookerii和Narthecium ossifragum 中分离出来的基于胆固醇的植物类固醇。迄今为止,尚未确定其 16-和 22-羟基的构型。在这项研究中,所有四种 16,22-立体异构体都是化学合成的。的1 H和13 C NMR光谱使用2D NMR技术完全分配,并测定明确使用X射线晶体结构。产物 NMR 谱中的 H-18 和 H-22 信号可用于确定 16-和 22-羟基的构型。核磁共振的比较,[α] D, 以及四种异构体与天然 calibagenin 和 Saxosterol 的 mp 数据证实,前者和后者的 16- 和 22- 羟基的构型分别与 16β,22 S和 16β,22 R相同。