Total Synthesis of Neo-Tanshinlactones through a Cascade Benzannulation-Lactonization as the Key Step
作者:Ketaki Ghosh、Raju Karmakar、Dipakranjan Mal
DOI:10.1002/ejoc.201300102
日期:2013.7
The cascade annulation-lactonization of phthalides with α-carboxyfurylacrylates in the presence of lithium hexamethyldisilazide (LiHMDS) provides both convergent and semiconvergent regioselective syntheses of neo-tanshinlactones in moderate yields. This methodology also offers an avenue for the direct syntheses of hitherto unreported 6-alkoxycarbonyl-substituted neo-tanshinlactones and their heterocyclic
在六甲基二硅肼锂 (LiHMDS) 存在下,邻苯二甲酸酯与 α-羧基呋喃基丙烯酸酯的级联环化 - 内酯化以中等产率提供了新丹参内酯的会聚和半会聚区域选择性合成。该方法还为迄今为止未报道的 6-烷氧基羰基取代的新丹参内酯及其杂环类似物的直接合成提供了途径。基于 Duff 反应和 Furstner 交叉偶联的组合开发了 4-烷基苯酞的新合成方法。