Different Cu catalysts have been used for the hydrogenation of very low value mint oils, namely, dementholized cornmint oil and Spanish pennyroyal oil. During the hydrogenation of dementholized oil Cu/Al2O3 showed the best activity and selectivity towards a mixture of menthols, while stereoselectivity toward the valuable isomer (-)-menthol can be improved by selectively dehydrogenating the products mixture. In the hydrogenation of pulegone and pennyroyal oil Cu/Al2O3 showed an unprecedented activity allowing complete transformation of the substrate into menthols under very mild experimental conditions (1 atm H-2, 90 degrees C). Moreover, a dynamic kinetic resolution process taking place during the hydrogenation step, allows to enrich the mixture in (-)-menthol. (c) 2006 Elsevier B.V. All rights reserved.