Cynaropicrin is a guaianolide sesquiterpene lactone, which has potent in vitro and in vivo inhibitory activity against Trypanosoma brucei, the protozoan parasite that causes human African trypanosomiasis (HAT; sleeping sickness). Herein, we describe the synthesis of cynaropicrin's deuterated derivative, cynaropicrin-d(4), by the replacement of the side chain of natural cynaropicrin. The synthesized cynaropicrin-d(4) could be employed as an internal standard for liquid chromatography-mass spectrometry (LC-MS) analysis, in the pharmacokinetic study of cynaropicrin. This could potentially advance the study of this therapeutic lead. (C) 2015 Elsevier Ltd. All rights reserved.
A RhIII‐catalyzed intramolecularoxidative cross‐coupling between double bonds for the synthesis of macrolides is described. Under the optimized reaction conditions, macrocycles containing a diene moiety can be formed in reasonable yields and with excellent chemo‐ and stereoselectivity. This method provides an efficient approach to synthesize macrocyclic compounds containing a 1,3‐conjugated diene
Rifamycin Biosynthetic Congeners: Isolation and Total Synthesis of Rifsaliniketal and Total Synthesis of Salinisporamycin and Saliniketals A and B
作者:Yu Feng、Jun Liu、Yazmin P. Carrasco、John B. MacMillan、Jef K. De Brabander
DOI:10.1021/jacs.6b03248
日期:2016.6.8
We describe the isolation, structure elucidation, and totalsynthesis of the novel marine naturalproduct rifsaliniketal and the totalsynthesis of the structurally related variants salinisporamycin and saliniketals A and B. Rifsaliniketal was previously proposed, but not observed, as a diverted metabolite from a biosynthetic precursor to rifamycin S. Decarboxylation of rifamycin provides salinisporamycin
我们描述了新型海洋天然产物利夫沙林酮的分离、结构解析和全合成,以及结构相关变体盐孢霉素和盐酮 A 和 B 的全合成。 利夫沙林酮先前被提出,但未观察到,作为来自生物合成的转移代谢物利福霉素 S 的前体。利福霉素脱羧产生盐孢霉素,它在截断并失去萘醌环后产生盐缩酮。我们的合成策略取决于 Pt(II) 催化的炔二醇环异构化以设置二氧杂双环 [3.2.1] 辛烷环系统和中间体二氢吡喃酮的碎片化以形成立体化学定义的 (E,Z)-二烯酰胺单元。探索了多种途径来组装具有高度立体控制的片段,在立体化学复杂的片段组装过程中提供了对无环立体控制的额外见解的练习。由此产生的盐缩酮的 11-14 步合成使我们能够探索合成和偶联高度取代的萘醌或相应的萘片段的策略。尽管与萘醌片段的直接偶联被证明是不成功的,但酰胺化和 CN 键形成策略与更富电子的萘同系物提供了一种有效的手段来完成利沙林酮和盐孢霉素的首次全合成。由此产生的盐缩酮的
Biology-Oriented Synthesis of a Withanolide-Inspired Compound Collection Reveals Novel Modulators of Hedgehog Signaling
Biology‐oriented synthesis employs the structural information encoded in complex natural products to guide the synthesis of compoundcollections enriched in bioactivity. The trans‐hydrindane dehydro‐δ‐lactone motif defines the characteristic scaffold of the steroid‐like withanolides, a plant‐derived natural product class with a diverse pattern of bioactivity. A withanolide‐inspired compoundcollection was synthesized
highly selective aldol fragment coupling whose stereochemical outcome is influenced by a gamma-stereogenic methyl group, and an interesting one-pot desilylation/dihydropyranone fragmentation/amidation sequence. As such, saliniketalB was obtained in 11 steps and 23% overall yield from commercially available starting material via a convergent coupling of two equally complex fragments assembled in seven
我们报告了海洋放线菌衍生的天然产物盐缩酮 B 的简洁、对映选择性和高效合成。 . 我们的策略强调了我们实验室开发的 Pt(II) 介导的炔二醇环异构化的效用,以构建二氧杂双环 [3.2.1] 辛烷环系统,这是一种高度选择性的醛醇片段偶联,其立体化学结果受伽马立体甲基的影响,以及有趣的一锅脱甲硅烷基化/二氢吡喃酮片段化/酰胺化序列。像这样,
Late-Stage Diversification through Manganese-Catalyzed C−H Activation: Access to Acyclic, Hybrid, and Stapled Peptides
Bioorthogonal C−H allylation with ample scope was accomplished through a versatile manganese(I)‐catalyzedC−Hactivation for the late‐stagediversification of structurally complex peptides. The unique robustness of the manganese(I) catalysis manifold was reflected by full tolerance of sensitive functional groups, such as iodides, esters, amides, and OH‐free hydroxy groups, thereby setting the stage for the