期刊
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
卷 2009, 期 13, 页码 2130-2140出版社
WILEY-V C H VERLAG GMBH
DOI: 10.1002/ejoc.200801278
关键词
Polyketides; Lichen metabolites; Resorcylic lactones; Cross-coupling; Dakin reaction; Total synthesis
资金
- Jurgen-Manchot-Stiftung
- Studienstiftung des Deutschen Volkes
- Stiftung der Deutschen Wirtschaft
Graphislactones A-H and the structurally related ulocladol are highly oxygenated resorcylic lactones produced by lichens and fungi. We present total syntheses of graphislactones A, C-F, H and of ulocladol. Graphislactones E, F, and H were synthesized for the first time. The spectra of graphislactones E and F synthesized as the originally proposed structures were not in agreement with published data, Consequently, revised structures for these compounds are proposed, whose correctness is unambiguously proven by total synthesis and comparison of the spectroscopic data. Key steps in all syntheses are Suzuki couplings for the construction of the central biaryl bond and Dakin reactions to supply further hydroxy groups required in these highly oxygenated substrates. Graphislactones A, C, and H, acylated graphislactone D and ulocladol were prepared in 8-11 steps with 7-20% yield starting with purchasable compounds, where the longest linear sequence consists of 5-9 steps. The syntheses are thus significantly shorter than the previously published syntheses of graphislactones A-D and of ulocladol. Graphislactones E and F were synthesized in 8 steps, where the longest linear sequences consist of 6 and 5 steps, respectively. They were isolated as the respective acetylated compounds with 25 and 10%, yield. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据