Isomerization of dihydroazulenes to substituted azulenes - naked eye observation of a novel Cope-type rearrangement.
作者:Klaus Hafner、Jens Hartung、Claudia Syren
DOI:10.1016/s0040-4020(01)81580-5
日期:1992.6
Readily accessible 3a-bridgehead allylic or propargylic substituted dihydroazulenes 9 rearrange at room temperature to thermodynamic more stable substituted azulenes. This process is parallel by a gradual change in color: the yellow solution of the starting pentaenes e.g. 9a smoothly turns to green and finally to the brilliant blue of 10a at the end of the reaction. Activation parameters for one example
易于获得的3a-桥头烯丙基或炔丙基取代的二氢azulenes 9在室温下重排为热力学更稳定的取代的天青烯。该过程与颜色的逐渐变化是平行的:反应结束时,起始戊烯(例如9a)的黄色溶液逐渐变为绿色,最后变为10a的亮蓝色。给出了这类反应的一个实例的活化参数。描述了9a和一些衍生物的合成,该衍生物进行了这种重排过程。