Oxidation of cyclohexene to trans-1,2-cyclohexanediol promoted by p-toluenesulfonic acid without organic solvents

摘要

This experiment describes a method for cyclohexene oxidation to trans-1,2-cyclohexanediol using p-toluenesulfonic acid (p-TsOH) as promoter and hydrogen peroxide as oxidant in a biphasic system. This method allows conversions up to 97.9% (monitored by ~1H NMR). trans-1,2- Cyclohexanediol was not easily separated from the aqueous solution owing to formation of an azeotropic mixture with water. Destruction of the azeotropic mixture was observed in the presence of sodium p-toluenesulfonate salt (p-TsONa). Therefore, water could be removed by simple distillation after p-TsOH neutralization. Purification of trans-1,2-cyclohexanediol was accomplished by sublimation. The overall reaction, separation, and purification experiment did not require any organic solvent.