Ring-Opening Reactions of Aziridines Fused to a Conformationally Locked Tetrahydropyran Ring
作者:JindrÌich Karban、JirÌà Kroutil、MilosÌ BudeÌsÌÃnský、Jan Sýkora、Ivana CÃsarÌová
DOI:10.1002/ejoc.200900762
日期:2009.12
6-Anhydro-2,3,4-trideoxy-2,3-(tosylepimino)-β-D-hexopyranoses 1 and 2 underwent aziridine ring-opening reactions with halides and other heteroatom-centered nucleophiles. Ribo-epimine 1 provided trans-diaxial and cis products. The lyxo-epimine 2 gave trans-diaxial and trans-diequatorial products, depending upon the reaction conditions (acid cleavage versus base cleavage) and the nucleophile (hard nucleophiles
1,6-Anhydro-2,3,4-trideoxy-2,3-(tosylepimino)-β-D-hexopyranoses 1 和 2 与卤化物和其他以杂原子为中心的亲核试剂发生氮丙啶开环反应。Ribo-epimine 1 提供了跨双轴和顺式产品。lyxo-epimine 2 产生反双轴和反双赤道产物,这取决于反应条件(酸裂解与碱裂解)和亲核试剂(硬亲核试剂与软亲核试剂)。通过假设 SN2 和边界 SN2 切割机制都有效,这些结果已被合理化。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)