A CONVENIENT METHOD OF SYNTHESIS OF MESOMORPHIC 2,5-DISUBSTITUTED CYCLOHEXAN-1-ONES BY A CATALYTIC REDUCTION OF 3,6-DISUBSTITUTED CYCLOHEX-2-EN-1-ONES

The preparation of trans-2,5-disubstituted cyclohexan-1-ones from 3,6- disubstituted cyclohex-2-en-1-ones by reduction with hydrogen in the p resence of palladium on carbon in a basic medium is described. The nat ure of the mesomorphic phases together with some physical properties o f single compounds and of nematic mixtures comprising them are reporte d. Mesogens containing the trans-2,5-disubstituted cyclohexan-1-one ri ng show a small negative dielectric anisotropy and a low birefringence .