Stereodivergent Synthesis of Iminosugars from Stannylated Derivatives of (S)‑Vinylglycinol

An original access to iminosugars from a cis/trans mixture of stannylated oxazolidinones 5 is reported. The dehydropiperidines 7-trans and 7-cis were obtained stereoselectively with an RS and SS configuration depending on the order of the Sn–Li transmetalation (followed by electrophilic trapping) and of the ring closing metathesis reactions due to the stereoselective epimerization of the α-aminoanion intermediate. The dehydropiperidines 7-trans and 7-cis were subsequently used for the synthesis of enantiopure homonojirimycin analogs.

本报告揭示了从锡烷基氧杂唑啉酮5的顺/反混合物中直接获取次氨基糖的原始方法。通过立体选择性地采用RS和SS构型，根据Sn–Li跨金属化（随后进行亲电捕获）以及由于α-氨基阴离子中间体的立体选择性外消旋化而引发的环闭合转位反应的顺序，成功获得了去氢吡哌啶7-顺和7-反异构体。去氢吡哌啶7-顺和7-反异构体随后被用于合成对映纯单诺吉霉素类衍生物。