des-epoxy-amphidinolide N 的合成在 22 个最长的线性步骤和 33 个总步骤中实现。本文报道了三代合成努力。在第一代中,我们的关键拼接策略突出了分子内 Ru 催化的烯烃 - 炔 (Ru AA) 偶联和后期环氧化,证明是成功的,但使用二羟基化方法安装 α,α'-二羟基酮基序有问题。我们的第二代合成工作解决了南片段合成的可扩展性问题,并显着提高了原子经济 Ru AA 偶联的效率,但遇到了几个基于保护基的问题,这些问题被证明是无法克服的。最后,依靠明智的保护组策略以及简洁的片段准备,des-epoxy-amphidinolide N 以收敛的方式实现。计算揭示了amphidinolide N 内的氢键桥。使用我们合成的脱环氧-amphidinolide N 比较13C NMR 化学位移差异表明amphidinolide N 和carbenolide I 可能相同。
Elaborate fragments of the proposed stereostructure of the complex polyketide antibiotic vancoresmycin have been synthesized in a stereoselective fashion based on a modular and convergent approach. Significant nuclear magnetic resonance differences in one of these subunits compared with the natural product question the proposed stereoconfiguration. Consequently, an extensive bioinformatics analysis
Total Synthesis of (+)-Roxaticin via C−C Bond Forming Transfer Hydrogenation: A Departure from Stoichiometric Chiral Reagents, Auxiliaries, and Premetalated Nucleophiles in Polyketide Construction
作者:Soo Bong Han、Abbas Hassan、In Su Kim、Michael J. Krische
DOI:10.1021/ja1082798
日期:2010.11.10
A totalsynthesis of the oxo-polyene macrolide (+)-roxaticin is achieved in 20 steps from 1,3-propanediol. In this approach, 9 of 10 C-C bonds formed in the longest linear sequence are made via metal catalysis, including 7 C-C bonds formed by iridium catalyzed alcohol C-C coupling. Notably, the present synthesis, which represents the most concise preparation of any oxo-polyene macrolide reported to
氧代多烯大环内酯 (+)-roxaticin 的全合成由 1,3-丙二醇分 20 步完成。在这种方法中,最长线性序列中形成的 10 个 CC 键中有 9 个是通过金属催化形成的,其中 7 个 CC 键是通过铱催化的醇 CC 偶联形成的。值得注意的是,本合成是迄今为止报道的任何氧代多烯大环内酯的最简洁的制备方法,它是在没有手性试剂和手性助剂的情况下实现的,并且使用最少的预金属化 C-亲核试剂。