Synthesis and Conformational Analysis of Bicyclic Sulfonium Salts. Structures Related to the Glycosidase Inhibitor Australine
作者:Nag S. Kumar、B. Mario Pinto
DOI:10.1021/jo051560p
日期:2006.4.1
The syntheses of eight sulfonium compounds with structures related to the naturally occurring pyrrolizidine alkaloid, australine, in which the bridgehead nitrogen atom is replaced by a sulfonium ion, are described. The synthetic strategy relies on the intramolecular attack of a cyclic thioether across a terminal double bond in the presence of a suitable electrophile. We postulate that these compounds
描述了八种sulf化合物的合成,这些化合物具有与天然存在的吡咯并iz烷生物碱,澳新碱有关的结构,其中桥头氮原子被sulf离子取代。合成策略依赖于在合适的亲电试剂存在下环状硫醚通过末端双键的分子内攻击。我们假设这些化合物在硫原子上具有永久的正电荷,将在糖苷酶催化的水解反应中模拟高度不稳定的氧杂碳鎓离子过渡态。基于1 H- 1的分析,这些化合物的构象偏爱H邻位耦合常数和1D-NOESY数据归因于空间和静电相互作用。这些化合物将用于与糖苷酶的构效关系研究。