Synthetic Studies toward C-Glucosidic Ellagitannins: A Biomimetic Total Synthesis of 5-O-Desgalloylepipunicacortein A
作者:Gaëlle Malik、Anna Natangelo、Jaime Charris、Laurent Pouységu、Stefano Manfredini、Dominique Cavagnat、Thierry Buffeteau、Denis Deffieux、Stéphane Quideau
DOI:10.1002/chem.201200517
日期:2012.7.16
5‐O‐desgalloylepipunicacortein A (1 β) was achieved by either using the natural ellagic acid bis‐lactone as a precursor of the requested HHDP unit or by implementing an atroposelective intramolecular oxidative biarylic coupling to forge this HHDP unit. Both routes converged in the penultimate step of this synthesis to enable a biomimetic formation of the key C‐aryl glucosidic bond in the title compound.
C-葡糖苷鞣花单宁是具有强抗氧化性能的生物活性多酚天然产物的一个子类,以及与它们与功能蛋白和结构蛋白相互作用的能力有关的有希望的抗肿瘤和抗病毒活性。迄今为止,大多数针对鞣花单宁的合成研究都涉及吡喃葡糖苷类。正在开发一种合成策略以获取C葡糖苷鞣花单宁,其特征结构特征包括通过C芳基葡糖苷键与开链葡萄糖核连接的促转异构六氢二苯甲酰基(HHDP)或九羟基二苯甲酰(NHTP)单元。本文所述。含二元HHDP的5- O的总合成通过使用天然鞣花酸双内酯作为要求的HHDP单元的前体或通过实施熵选择性分子内氧化双芳基偶合以锻造该HHDP单元,可以实现desgalloylepipunicacortein A(1β)。两种途径都在该合成的倒数第二个步骤中收敛,从而能够在目标化合物中仿生形成关键的C-芳基糖苷键。