Production of cyclic alcohols

Cyclic alcohols are important starting materials for production of many chemical specialties. Cyclohexanol is an intermediate in adipic acid and e-caprolactam technologies and it is also used as a solvent in chemical production. Cyclopentanol is often used in textile industry and in fragrances or fungicides production. Cyclic alcohols are manufactured by various processes and all of them have their limitations. Oxidation of cyclohexane is problematic due to the bad selectivity and low conversion level. Hydrogenation of phenol suffers from a high price of the starting feedstock. In recent years, some researchers have started to focus on direct and indirect hydrations of cyclic alkenes. The aim of this short review is to present the established methods and to summarize the published articles dealing with the hydration of cyclic alkenes. The direct hydration over zeolite catalysts and the indirect hydration in the presence of formic acid are widely described.