New troponoid liquid crystals (1–4) with a bitropone core were prepared. The ester derivatives (1) had enantiotropic smectic A and/or C phases with higher thermal stabilities than the corresponding benzenoid derivatives (5), which had a smectic B phase. The amide derivatives (3) had an enantiotropic smectic A phase, but the ether (2) and alkylamine (4) derivatives were not mesomorphic. The crystals of 1c had a layer structure with an intermolecular π–π interaction between the bitropone cores. X-ray diffraction studies revealed that the layer spacings of the smectic A and C phases of 1i were not very much different.