Total synthesis of 1-hydroxydehydroherbarin and ascomycones A, B, naphthoquinone antibiotics
摘要:
The first total synthesis of 1-hydroxydehydroherbarin and ascomycones A and B is reported. The biologically interesting ascomycones A and B were obtained in 18% overall yield starting from 3-chloro-2,5-dimethoxybenzaldehyde as building block.
Exploring O-stannyl ketyl and acyl radical cyclizations for the synthesis of γ-lactone-fused benzopyrans and benzofurans
作者:Helen Santoso、Myriam I. Casana、Christopher D. Donner
DOI:10.1039/c3ob42090f
日期:——
The synthesis of a series of γ-lactone-fused benzopyrans and benzofurans, analogues of the pyranonaphthoquinone antibiotics, is reported. Preparation of the heterocycles was achieved by either O-stannyl ketyl or acyl radicalcyclization of benzaldehyde precursors followed by oxidation to give the pyrano- and furanobenzoquinone systems. The observed diastereoselectivity during O-stannyl ketyl radical
The first total synthesis of epi-cochlioquinone A has been achieved in a highly convergent manner via [3+3] cycloaddition of catechol 2 and oxadecalin 3 as the key reaction. The synthesis of the catechol segment, possessing the side chain with multi stereogenic centers, features the asymmetricvinylogous Mukaiyama aldolreaction, the stereoselective conjugate addition to the nitroalkene, the stereospecific
Synthesis of novel pyranoquinones using an acyl radical cyclization strategy
作者:Christopher D. Donner、Myriam I. Casana
DOI:10.1016/j.tetlet.2011.12.084
日期:2012.2
Hindered β-benzyloxyacrylates cyclize efficiently providing a tin-free radical cyclization approach to the serine/threonine kinase AKT inhibitor frenolicin B, whilst γ-aryloxy crotonates give good yields of benzopyran-4-ones. This method is applied to the synthesis of a novel tetracyclic analogue of the pyranonaphthoquinone antibiotics.
Total Synthesis of Viridicatumtoxin B and Analogues Thereof: Strategy Evolution, Structural Revision, and Biological Evaluation
作者:K. C. Nicolaou、Christopher R. H. Hale、Christian Nilewski、Heraklidia A. Ioannidou、Abdelatif ElMarrouni、Lizanne G. Nilewski、Kathryn Beabout、Tim T. Wang、Yousif Shamoo
DOI:10.1021/ja506472u
日期:2014.8.27
critical reactivity patterns. The herein described synthetic strategy resulted in the totalsynthesis of viridicatumtoxin B (1), which, in turn, formed the basis for the revision of its originally assigned structure. The developed chemistry facilitated the synthesis of a series of viridicatumtoxin analogues, which were evaluated against Gram-positive and Gram-negative bacterial strains, including drug-resistant
描述了绿藻毒素 B (1) 全合成的细节。针对这种有趣的四环素抗生素的初步合成策略导致了关键的烷基化和路易斯酸介导的螺环化反应的发展,以形成受阻的 EF 螺结,以及迈克尔-迪克曼反应来设置 A 和 C 环。然而,发现使用芳族 A 环底物不适于在碳 4a 和 12a 处引入必需的羟基。应用这些先前的策略,我们分别开发了基于烯醇和烯醇盐氧化的逐步方法来氧化碳 12a 和 4a,后者是在揭示关键反应模式的系统研究之后完成的。本文所述的合成策略导致了绿藻毒素 B (1) 的全合成,进而形成了对其最初指定结构进行修订的基础。开发的化学促进了一系列绿藻毒素类似物的合成,这些类似物针对革兰氏阳性和革兰氏阴性细菌菌株进行了评估,包括耐药病原体,揭示了这种结构类型中的第一个结构-活性关系。
Experimental and Computational Investigations of the Reactions between α,β‐Unsaturated Lactones and 1,3‐Dienes by Cooperative Lewis Acid/Brønsted Acid Catalysis
作者:Anja Weber、Martin Breugst、Jörg Pietruszka
DOI:10.1002/ange.202008365
日期:2020.10.12
AbstractThe reactions of α,β‐unsaturated δ‐lactones with activated dienes such as 1,3‐dimethoxy‐1‐[(trimethylsilyl)oxy]‐1,3‐butadiene (Brassard's diene) are barely known in literature and show high potential for the synthesis of isocoumarin moieties. An in‐depth investigation of this reaction proved a stepwise mechanism via the vinylogous Michael‐products. Subsequent cyclisation and oxidation by LHMDS