The first total synthesis of the bacterial RNA-polymerase inhibitor ripostatin A (1) was achieved. The route utilizes a cyclic methyl acetal intermediate and a sequence of a double Stifle cross-coupling reaction followed by a ring-closing metathesis for the construction of the macrolactone ring. Additionally, an unprecedented formation of the 4-methoxy substituted tetrahydropyrans was observed during the acid catalyzed acetalization of the beta,delta-dihydroxyketone.
The first total synthesis of the bacterial RNA-polymerase inhibitor ripostatin A (1) was achieved. The route utilizes a cyclic methyl acetal intermediate and a sequence of a double Stifle cross-coupling reaction followed by a ring-closing metathesis for the construction of the macrolactone ring. Additionally, an unprecedented formation of the 4-methoxy substituted tetrahydropyrans was observed during the acid catalyzed acetalization of the beta,delta-dihydroxyketone.
Synthesis and Evaluation of Novel Analogues of Ripostatins
作者:Wufeng Tang、Shuang Liu、David Degen、Richard H. Ebright、Evgeny V. Prusov
DOI:10.1002/chem.201403176
日期:2014.9.15
Ripostatins are polyene macrolactones isolated from the myxobacterium Sorangium cellulosum. They exhibit antibiotic activity by inhibiting bacterial RNApolymerase (RNAP) through a binding site and mechanism that are different from those of current antibacterial drugs. Thus, the ripostatins serve as starting points for the development of new anti‐infective agents with a novel mode of action. In this
Ripostatins 是从粘杆菌 Sorangium cellulosum 中分离出来的多烯大环内酯. 它们通过与当前抗菌药物不同的结合位点和机制抑制细菌 RNA 聚合酶 (RNAP),从而表现出抗生素活性。因此,ripostatins 作为开发具有新作用模式的新型抗感染剂的起点。在这项工作中,产生了几种 ripostatins 的衍生物。15-Desoxyripostatin A 是通过使用一锅碳铝化/交叉偶联合成的。5,6-Dihydroripostatin A 是通过利用分子内 Suzuki 交叉偶联大内酯化方法构建的。14,14'-Difluororipostatin A 和差向异构 14,14'-difluororipostatin B 是通过使用 Reformatsky 型羟醛加成卤代酮、Stille 交叉偶联和闭环复分解合成的。介绍了 RNAP 抑制和抗菌活性。