The title indolizidine, a ring-modified analog of the potent mannosidase inhibitor (-)-swainsonine, has been prepared by intramolecular nucleophilic addition of the sp2-type nitrogen atom of a preformed 1,3-oxazine-2-thione heterocycle to the masked aldehyde group in a d-mannose precursor; the stereochemistry of the generated aminoacetalic stereocenter is governed by the generalized anomeric effect, the pseudoanomeric hydroxyl group adopting an axial orientation that mimics that of α-d-mannopyranoside aglycons.
标题中的
吲哚利嗪是强效
甘露糖苷酶
抑制剂 (-)-swainsonine 的环改性类似物,它是通过将预先形成的 1,3-oxazine-2-thione 杂环的 sp2 型氮原子与 d-mannose 前体中的遮蔽醛基进行分子内亲核加成而制备的;生成的
氨基
乙醛立体中心的立体
化学受广义同分异构体效应的支配,假同分异构体羟基的轴向取向与 δ-d-mannopyranoside aglycons 的轴向取向相似。