作者:Scott A. Snyder、Trevor C. Sherwood、Audrey G. Ross
DOI:10.1002/anie.201002264
日期:——
A polycyclic collapse: Use of a carefully designed acyclic intermediate participated in a cascade reaction that formed the entire core of the polyketide‐derived dalesconols in a single flask (see scheme). A number of additional and carefully controlled synthetic operations completed an expeditious synthesis of both of these highly bioactive natural products as well as structural congenors.
immunosuppressants (+)-dalesconol A and B in a highly efficient and concise manner, which features an efficient palladium-catalyzed enantioselective dearomative cyclization-kinetic resolutioncascade to install the chiralall-carbonquaternarycenter, an effective sterically hindered Stille coupling, a powerful 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) oxidation to furnish all requisite unsaturation, and a tandem
我们在此以高效简洁的方式报告了免疫抑制剂 (+)-dalesconol A 和 B 的首次对映选择性合成,其特点是高效的钯催化对映选择性脱芳环化-动力学拆分级联反应安装手性全碳四元中心,有效的空间位阻斯蒂尔偶联、强大的 2,3-二氯-5,6-二氰基-1,4-苯醌 (DDQ) 氧化以提供所有必需的不饱和度,以及串联水解-闭环序列。
Total Synthesis of Dalesconol A by Pd(0)/Norbornene-Catalyzed Three-Fold Domino Reaction and Pd(II)-Catalyzed Trihydroxylation
作者:Ping Zhao、Yun Guo、Xinjun Luan
DOI:10.1021/jacs.1c12118
日期:2021.12.22
Herein, we describe a concise totalsynthesis of dalesconol A through a “polycyclization/oxidation” approach. In the polycyclization stage, a Pd(0)/NBE-catalyzed 3-fold domino reaction and a subsequent intramolecular Michael addition have been utilized for the one-step assembly of the heptacyclic molecular skeleton. In the late stage of oxidation state adjustments, a stepwise sequence including site-selective
Immunosuppressive Polyketides from Mantis-Associated<i>Daldinia eschscholzii</i>
作者:Ying L. Zhang、Jie Zhang、Nan Jiang、Yan H. Lu、Lu Wang、Su H. Xu、Wei Wang、Gao F. Zhang、Qiang Xu、Hui M. Ge、Jing Ma、Yong C. Song、Ren X. Tan
DOI:10.1021/ja110932p
日期:2011.4.20
Polyketides with unknown architectures are highly desired for the discovery of new drugs and agrochemicals. Here, the mantis-associated Daldinia eschscholzii, a fungus known to produce immunosuppressants dalesconols A and B, was found to simultaneously generate four novel skeletons capable of shaping the unusual chemistry of the fungal polyketides, of which seven were structurally unique and substantially
具有未知结构的聚酮化合物是发现新药和农用化学品的迫切需要。在这里,与螳螂相关的 Daldinia eschscholzii(一种已知会产生免疫抑制剂 dalesconols A 和 B 的真菌)被发现同时产生四种新型骨架,能够塑造真菌聚酮化合物的不寻常化学,其中七种在结构上是独特的,并且具有显着的免疫抑制作用。特别是,微生物的放大发酵能够对次要或“过渡”中间聚酮化合物进行结构表征,从而可以合理识别分别由四个、五个、六个和八个乙酸酯单元缩合引发的四种生物合成途径。此外,三酮的脱羰反应,如在 daeschol A 的情况下,除了孢子丝蛋白 C 和结节酮的结构校正外,首次描述了。该工作提供了一组对药物发现具有重要意义的新型免疫抑制分子。
[EN] SYNTHESIS OF THE POTENT IMMUNOSUPPRESSANT AGENTS DALESCONOL A AND B<br/>[FR] SYNTHÈSE DES AGENTS IMMUNOSUPPRESSIFS PUISSANTS, LE DALESCONOL A ET B