Cis/trans-Isomerization of Cyclohexylbenzene Derivatives

Abstract

Liquid crystalline materials generally possess a 1,4-disubstituted cyclohexane skeleton as a common structural component. And it is well-known that the commercially available process for the synthesis of these compounds produces a mixture of cis- and trans-isomers, but only the trans-isomers are useful as liquid crystalline materials. Therefore, it is hopefully required to find an effective method to isomerize cis-isomers into the corresponding trans-ones. Fortunately, we found that this type of isomerization was efficiently promoted by addition of TfOH. The general scope of this reaction will be reported.