Alternative General Synthetic Routes to [2.2]Cyclophanes and [3.2]Cyclophanes from [3.3]Cyclophane-2,11-diones by Photodecarbonylation, and a Structural Study of [3.2]Metacyclophanes
作者:Hajime Isaji、Mikio Yasutake、Hiroyuki Takemura、Katsuya Sako、Hitoshi Tatemitsu、Takahiko Inazu、Teruo Shinmyozu
DOI:10.1002/1099-0690(200107)2001:13<2487::aid-ejoc2487>3.0.co;2-f
日期:2001.7
Photodecarbonylation of [3.3]cyclophane-2,11-diones, which are readily prepared by TosMIC coupling, affords [2.2]cyclophanes in high yield. This method also provides a general synthetic method for [3.2]cyclophan-2-ones by taking advantage of the fact that this photochemical reaction proceeds in a stepwise manner through [3.2]cyclophan-2-ones. A series of [2.2]cyclophanes, [3.2]cyclophanes, and [3.3]cyclophanes
[3.3] 环烷-2,11-二酮的光脱羰,很容易通过 TosMIC 偶联制备,以高产率提供 [2.2] 环烷。该方法还利用[3.2]环芳-2-酮的光化学反应以逐步方式进行这一事实,提供了[3.2]环芳-2-酮的通用合成方法。因此,可以从常见的前体 [3.3] 环烷-2,11-二酮制备一系列 [2.2] 环烷、[3.2] 环烷和 [3.3] 环烷。与 [3.3] 环芳烃的首选顺式几何结构形成鲜明对比的是,[3.2] 环芳烃采用反几何结构,并且通过变温 1 H NMR 光谱观察到芳环反转过程。在结晶状态下,尽管桥长不对称,但反[3.2]环芳烃的两个芳环几乎平行;