We report the synthesis of iminosugar C,C-glycosides starting from 6-azidoketopyranoses. Their Staudinger-azaWittig-mediated cyclization provided bicyclic N,O-acetals, which were stereoselectively opened with AllMgBr to afford β-hydroxyazepanes with a quaternary carbon α to the nitrogen. Their ring contraction via a β-aminoalcohol rearrangement produced the six-membered l-iminosugars with two functional handles at the pseudoanomeric position. Inversion of the free OH at the azepane level furnished the d-iminosugars.

中文翻译：

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从 6-叠氮酮吡喃糖中立体选择性获取亚氨基糖 C,C-糖苷

我们报告了从 6-叠氮酮吡喃糖开始合成亚氨基糖C、C-糖苷。他们的施陶丁格-氮杂维蒂希介导的环化反应提供了双环N , O -缩醛，它们被 AllMgBr 立体选择性地开环，得到了氮上具有季碳 α 的 β-羟基氮杂环己烷。它们通过 β-氨基醇重排的环收缩产生了在假端基位置具有两个功能手柄的六元l-亚氨基糖。氮杂环乙烷水平的游离 OH 的转化提供了d-亚氨基糖。