五层龙属植物中提取的具有<i>α</i>-葡萄糖苷酶抑制活性的天然产物neokotalanol的全合成

五层龙属植物中提取的具有α-葡萄糖苷酶抑制活性的天然产物neokotalanol的全合成

摘要: 以苄基保护的硫糖和由D-甘露糖为起始原料,合成得到的三氟甲磺酸酯间的偶合反应作为关键反应合成了从五层龙属植物根茎部提取的具有很强-葡萄糖苷酶抑制活性的天然产物neokotalanol。研究发现该关键的偶合反应的产物是由反应温度直接决定的,反应除了得到目标锍糖化合物的同时,还分离出了通过经典的分子内成环反应所得到2,4,7-三氧代二环壬烷类衍生物。

Abstract: Neokotalanol,a potent -glucosidase inhibitor isolated from Salacia reticulata,was synthesized through a key coupling reaction between a perbenzylated thiosugar and an appropriately protected perseitol triflate derived from D-mannose.This key step was found to be quite temperature dependent,and a simultaneous cyclization of the triflate leading to a characteristic 2,4,7-trioxabicyclo4.2.1nonane system was detected.