The total synthesis of hyperpapuanone, hyperibone L, epi-clusianone and oblongifolin A
作者:Nicole Biber、Katrin Möws、Bernd Plietker
DOI:10.1038/nchem.1170
日期:2011.12
Polyprenylated polycyclic acylphloroglucines (PPAPs) are a family of natural products that possess a wide range of different important biological activities because of the relative position and configuration of four substituents that decorate one common central bicyclo[3.3.1]nonane-2,4,9-trione core. The rigid bicyclic framework with its lipophilic side chains and its hydrophilic trione moiety represents a nature-derived lead structure that arranges the substituents (R1 to R4) into a defined topographical orientation. As the substituents are responsible for the biological activities, the seven-step synthetic approach presented here sets the stage for an iterative introduction of R1 to R4 and thus generates structurally diverse trans-type B PPAPs. Four natural and one non-natural trans-type B PPAPs were prepared starting from acetylacetone with overall yields that ranged from 6 to 22%. The concept of separating framework construction from decorating transformations plus the minimization of protecting-group operations are the key issues for the realization of our synthetic approach. The polyprenylated polycyclic acylphloroglucines (PPAPs) are a family of natural products in which a common core is decorated with four different substituents. Here, a synthetic strategy is presented that separates the core building steps from the core decorating steps, offering a general solution to the synthesis of these natural products that will allow investigation of their biological activities.
多烯化多环酰基氯葡萄糖(PPAPs)是一个天然产品家族,由于装饰一个共同的中心双环[3.3.1]壬烷-2,4,9-三酮核心的四个取代基的相对位置和构型不同,因此具有多种不同的重要生物活性。具有亲油性侧链和亲水性三酮分子的刚性双环框架代表了一种源自自然的先导结构,它将取代基(R1 至 R4)排列成确定的地形方向。由于取代基具有生物活性,本文介绍的七步合成方法为 R1 至 R4 的迭代引入创造了条件,从而产生了结构多样的反式 B 型 PPAP。从乙酰丙酮开始,制备了四种天然和一种非天然反式 B 型 PPAP,总产率在 6% 到 22% 之间。框架构建与装饰转化分离的概念以及保护基操作的最小化是实现我们合成方法的关键问题。多烯化多环酰基氯吡啶(PPAPs)是一个天然产品家族,其中一个共同的核心被四个不同的取代基所装饰。这里介绍的合成策略将核心构建步骤与核心装饰步骤分开,为这些天然产物的合成提供了一个通用解决方案,从而可以研究它们的生物活性。
The enantioselective total synthesis of (+)-clusianone
(+)-Clusianone, an exo-type B PPAP with reported anti-HIV and chemoprotective activities, was synthesized in eleven steps with 97% ee starting from acetylacetone.
novel drugs. Hyperforin, a natural type A polyprenylatedpolycyclicacylphloroglucinol from St. John’s wort, exhibits antidepressant and antibacterial effects also against Mtb. Yet, Hyperforin’s instability limits the utility in clinical practice. Here, we present photo- and bench-stable type B PPAPs with enhanced antimycobacterial efficacy. PPAP22 emerged as a lead compound, further improved as the
In the past 20 years, peptide‐based antibiotics, such as vancomycin, teicoplanin, and daptomycin, have often been considered as second‐line antibiotics. However, in recent years, an increasing number of reports on vancomycin resistance in pathogens appeared, which forces researchers to find novel lead structures for potent new antibiotics. Herein, we report the total synthesis of a defined endo‐type B