Approach to a New Dihydrofuran-Fused Cyclic System by a Remarkable Switching ofendo/exo Selectivity of a [4+2] Cycloaddition Reaction
作者:Yuji Matsuya、Yoshiaki Imamura、Tatsuro Miyahara、Hiroshi Ochiai、Hideo Nemoto
DOI:10.1002/ejoc.200701050
日期:2008.3
synthesis of a new class of dihydrofuran-fused tetracyclic compounds, possessing a 2-oxa-furano-steroidal framework, has been achieved by successive electrocyclic reactions of benzocyclobutene derivatives. It has been revealed that the stereoselectivity of a key intramolecular [4+2] cycloaddition reaction can be controlled by installation of a bulky silyl substituent onto the furan ring resulting in
通过苯并环丁烯衍生物的连续电环反应,已实现了具有 2-氧杂-呋喃-甾体骨架的新型二氢呋喃稠合四环化合物的有效合成。研究表明,关键的分子内 [4+2] 环加成反应的立体选择性可以通过在呋喃环上安装庞大的甲硅烷基取代基来控制,从而形成外加合物,这与我们过去观察到的选择性相反相关研究。已经对合成化合物的生物活性进行了初步检查,并表明它们具有作为抗流感药物的潜力。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)