Department of Biochemistry, University of Texas Southwestern Medical Center , 5323 Harry Hines Boulevard, Dallas, Texas 75390, United States.
J Am Chem Soc. 2016 Aug 24;138(33):10684-92. doi: 10.1021/jacs.6b06460. Epub 2016 Aug 11.
We report a concise total synthesis of dictyodendrin F and the first total syntheses of dictyodendrins H and I in six steps. In these syntheses, aryl ynol ethers were employed as the key building blocks to introduce aryl and heteroaryl rings in the dictyodendrins. This rapid synthesis utilized a novel hetero-[2 + 2]-cycloaddition reaction between two aryl ynol ethers to yield a cyclobutenone ring. The cyclobutenone was sequentially converted into a highly substituted carbazole via a retro-4π/6π-electrocyclization-N-acylation cascade reaction to provide the dictyodendrin core. Consecutive intramolecular oxidative coupling and deprotection gave dictyodendrins F, H, and I.
我们报告了二萜 F 的简洁全合成以及二萜 H 和 I 的首次全合成,总共六步。在这些合成中,芳基炔基醚被用作关键构建块,以在二萜中引入芳基和杂芳基环。这种快速合成利用了两个芳基炔基醚之间的新型杂[2+2]-环加成反应,生成环丁烯酮环。环丁烯酮通过反-[4π/6π]-电环化-N-酰化级联反应依次转化为高度取代的咔唑,提供二萜核心。连续的分子内氧化偶联和脱保护得到二萜 F、H 和 I。