The preparation oftrans-2,5-disubstituted cyclohexan-1-ones from 3,6-disubstituted cyclohex-2-en-1-ones by reduction with hydrogen in the presence of palladium on carbon in a basic medium is described. The nature of the mesomorphic phases together with some physical properties of single compounds and of nematic mixtures comprising them are reported. Mesogens containing thetrans-2,5-disubstituted cyclohexan-1-one ring show a small negative dielectric anisotropy and a low birefringence.