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龙脷叶中天然产物sauropunol A-D的全合成

Total synthesis of sauropunol A-D isolated from Sauropus rostratus genus plants

  • 摘要: Sauropunol A - D 是从中药龙脷叶中分离出的具有2-脱氧-3,6脱水呋喃己糖(苷)结构的化学成分,具有潜在抗炎、抗菌等生物活性。以2-脱氧-D-阿拉伯己糖为起始原料,经多步反应获得3,5-位以对甲氧基苄基保护的伯醇中间体,对其进行三氟甲磺酰化所得的三氟甲磺酸酯中间体会自动引发分子内关环反应从而构建2-脱氧-3,6-脱水-D-葡萄糖呋喃糖苷骨架结构。经脱保护反应,最终合成了sauropunol AB和C/D ,总产率分别为21%,5%和17%(互变异构体sauropunol C/D )。基于前期文献报道,对这4个化合物(sauropunol A - D )的结构进行了确证。

     

    Abstract: Sauropunol A-D potentially with anti-inflammatory, anti-bacterial activities were recently isolated from traditional Chinese medicinal plant Sauropus rostratus. Herein, we report the total synthesis of sauropunol( A - D )starting from a commercially available 2-deoxy-D-arabino-hexopyranose. The trifluoromethane sulfonation of intermediates could simultaneously trigger intramolecular cyclization to afford 3, 6-anhydro hexofuranoside scaffold. The following deprotection reaction could produce sauropunol A , B and C / D with total yields of 21%, 5%, and 17%(isomer sauropunol C / D ), respectively. Structures of the target compounds were confirmed by comparison with NMR spectroscopic properties of those previously reported.