Study On Synthesis And Isomerization Of Trans-4-(trans-4’-propylcyclohexyl)cyclohexanol

Cyclohexane derivatives were widely used in mixed liquid crystal for its goodperformance such as low viscosity,high stability and wide temperature phase. In ordertto keep the molecular rigid and linetype, its structure must keep the transconfigurational primarily. Therefore synthesis of trans configuration intermediates areparticularly important. It was rarely reported in domestic and international about themethods of isomerization through cis-isomers transformation for trans-isomers.Synthesis method of an liquid crystal intermediate4-(trans-4’-propylcyclohexyl)cyclohexanol was studied. The structure of the target compound andthe important intermediate was identified by gas-mass spectrometry (GC-MS),infrared spectroscopy (IR), nuclear magnetic resonance spectroscopy of carbon(13CNMR). The result shows that the target compounds are consistent to the expected.The reaction conditions of each step is more moderate. The total yield is24.8%.The innovation of this thesis was lie in the realized isomerization method throgh thecis-isomer changed into the trans-isomer. And the promoted research and mechanism isdiscussed. The experimental result that the transformation method is applicable forhomologue. Alkali metal such as sodium and potassium is applied. The cis-trans ratio of4-(trans-4’-propylcyclohexyl)cyclohexanol is changed from68:31to8:91with themethod of potassium after7hours. The method of cis-isomers into trans-isomersrealization that the yield of purified from8%increase to65～75%, greatly reduces thecost of trans-4-(trans-4’-n-propylcyclohexyl)cyclohexanol. It provides possibility thatthe liquid crystal compounds with the intermediate as the basic unit was designed. Andit is valuable for broadening the type of liquid crystals containing cyclohexane. In addition, the ethers and esters liquid crystal compounds were synthesized usingthe intermediates trans-4-(trans-4’-propylcyclohexyl)cyclohexanol as raw materials.Crystal phase temperature is determined. It provides a basis of the three liquid crystal.nd the determination compounds were evaluated through the performance effect of themixed liquid crystal.