In Pursuit ofcis,cis,cis-Cyclonona-2,5,8-triene-1,4,7-trione – An Adventure in Medium-Sized Ring Chemistry
作者:Axel Pleschke、Jens Geier、Manfred Keller、Jürgen Wörth、Lothar Knothe、Horst Prinzbach
DOI:10.1002/ejoc.200700397
日期:2007.10
synthesize the long soughtafter tris-π-homobenzene cis,cis,cis-2,5,8-cyclononatriene-1,4,7-trione, via the newly prepared cyclononane-1,4,7-trione (C9H6O3), through base-catalysed threefold HBr elimination from an efficiently prepared and stereochemically uniform tribromo derivative, failed due to typical medium-ring complications, transannular reactions and an exceptional ease of polymerization. In the cations
尝试通过新制备的环壬烷-1,4,7-三酮 (C9H6O3) 合成备受追捧的三-π-高苯 cis,cis,cis-2,5,8-cyclononatriene-1,4,7-trione,通过碱催化从有效制备且立体化学均匀的三溴衍生物中消除三重 HBr,由于典型的中环并发症、跨环反应和聚合异常容易而失败。在通过电子碰撞电离 (MS) 在气相中生成的阳离子中,(H)Br 的三重消除与 CO 的消除竞争导致 C9H7O3+ 离子,而令人印象深刻的整洁阴离子三步碎裂途径导致C9H6O3– 离子。虽然这些无溴离子的组成部分通过计算接近 B3LYP/6-31+G(d,p)},并且它们的分配似乎与质子化和阴离子目标分子兼容,但它们的真实性质仍然是开放的。提供了几种(桥接的)九元环化合物的 X 射线结构分析。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim