New mesogenic compounds with trans-stilbene oxide as the central chiral core

Several derivatives with the trans-stilbene oxide moiety as the central chiral core were synthesized. With the appropriate substituents, nematic and smectic C phases were observed. One derivative was obtained with an ee of 47 per cent by asymmetric synthesis. The chemical stability of these epoxides is low and they rearrange to give substituted phenyl benzylketones which are also liquid-crystalline. The structure of the two solid phases present in all the derivatives and of the smectic C phases was investigated by X-ray diffraction.