Department of Chemistry, University of York, Heslington, York, North Yorks, UK YO10 5DD.
Org Biomol Chem. 2011 Jul 21;9(14):5062-78. doi: 10.1039/c1ob05448a. Epub 2011 May 20.
A series of diverse natural product-like structures have been synthesised by the use of a number of novel transannulation reactions across a cyclononene ring. Transannular cyclisations through oxygen functionality have generated a number of bicyclo[5.3.1]systems containing bridged cyclic ethers and bicyclo[5.2.2]lactones, as well as a tetrahydrofuran-containing bridged analogue of hexacyclinic acid. An unprecedented Brønsted acid mediated transannular cyclisation between proximal carbons generated bicyclo[4.3.0]nonanes which form the core of the pinguisane and austrodorane families of sesquiterpenoids. In all cases the key factor that determined the mode of reactivity was the conformation of the nine-membered ring and the distance between the reacting centres.
一系列不同的天然产物样结构已通过在环壬烯环上使用多种新型的跨环反应来合成。 通过氧官能团的环加成反应生成了许多包含桥接环状醚和双环[5.2.2]内酯的双环[5.3.1]系统，以及六环酸的含四氢呋喃桥接类似物。 前所未有的 Brønsted 酸介导的两个靠近碳原子之间的跨环环化生成了双环[4.3.0]壬烷，其构成了倍半萜类化合物的 pinguisane 和 austrodorane 家族的核心。 在所有情况下，决定反应模式的关键因素是九元环的构象和反应中心之间的距离。
