Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, 35, Keyan Road, Zhunan Town, Miaoli County 35053, Taiwan, ROC.
Chemistry. 2011 Jul 25;17(31):8696-703. doi: 10.1002/chem.201100986. Epub 2011 Jun 16.
The first total synthesis of cytopiloyne 1, a novel bioactive polyacetylenic glucoside isolated from the extract of Bidens pilosa, is described. The structure of cytopiloyne was determined to be 2-β-D-glucopyranosyloxy-1-hydroxytrideca-5,7,9,11-tetrayne by using various spectroscopic methods, but the chirality of the polyyne moiety was unknown. Herein, the convergent synthesis of two diastereomers of cytopiloyne by starting from commercially available 4-(2-hydroxyethyl)-2,2-dimethyl-1,3-diozolane is described. The synthetic sequence involved two key steps: stereoselective glycosylation of the glucosyl trichloroacetimidate with 1-[(4-methoxybenzyl)oxy]hex-5-yn-2-ol to give the desired β-glycoside and the construction of the glucosyl tetrayne skeleton by using a palladium/silver-catalyzed cross-coupling reaction to form the alkyne-alkyne bond, the first such use of this reaction. Comparison between the observed and published characterization data showed the 2R isomer to be the natural product cytopiloyne.
从菊科植物三叶鬼针草的提取物中分离得到的新型生物活性聚乙炔葡萄糖苷细胞吡咯烷 1 的首次全合成描述。通过各种光谱方法确定细胞吡咯烷的结构为 2-β-D-吡喃葡萄糖苷氧基-1-羟基十三烷-5,7,9,11-四炔，但聚乙炔部分的手性未知。本文描述了从商业上可获得的 4-(2-羟乙基)-2,2-二甲基-1,3-二恶唑烷出发，通过会聚合成两种细胞吡咯烷的非对映异构体。合成序列包括两个关键步骤：用 1-[(4-甲氧基苄基)氧基]己-5-炔-2-醇对葡萄糖基三氯乙酰亚胺进行立体选择性糖苷化，得到所需的β-糖苷，以及通过钯/银催化的交叉偶联反应构建葡萄糖基四炔骨架，首次使用该反应。观察到的和已发表的特征数据的比较表明 2R 异构体为天然产物细胞吡咯烷。
