Abstract: An optically active lactone derivative represented by the following general formula (I): ##STR1## wherein R.sup.1 represents a straight-chain or branched alkyl, alkoxyl, alkanoyloxy, alkoxycarbonyl, alkoxyalkyl, alkoxyalkanoyloxy, or alkoxyalkoxyl group having 1 to 20 carbon atoms or an optically active group of each of the above kinds, R.sup.2 represents a straight-chain or branched alkyl group having 1 to 20 carbon atoms, ##STR2## or trans-1,4-cyclohexylene group of the formula and the asymmetric carbon atoms at the 2- and 4-positions in the lactone ring each independently is of the (S) or (R) configuration, an intermediate therefor, a process for producing the intermediate, a liquid-crystal composition, and a liquid-crystal display device.

Abstract: A 2,5-disubstituted pyrazine derivative and a 2,5-disubstituted pyrimidine derivative of the formula (I): ##STR1## wherein R.sup.1 and R.sup.2 each independently represents a straight-chain or branched alkyl group containing 1 to 20 carbon atoms;X represents a halogen atom; and ##STR2## represents a pyrazine-2,5-diyl or a pyrimidine-2,5-diyl group; each useful as an electrooptical display material are disclosed. Further a liquid crystal composition comprising said compounds as well as a ferroelectric display device wherein said liquid crystal composition is used are disclosed.

Abstract: A liquid crystalline compound represented by formula ##STR1## wherein R denotes an alkyl or alkoxy group having 1 to 20 carbon atoms,m and n are each 0 or 1, provided m and n are not 1 at the same time. ##STR2## X and Y each denote a hydrogen atom, a halogen atom or a nitro group, provided X and Y are not hydrogen atoms at the same time, andQ* denotes an optically active group having an asymmetric carbon atom and a linear or cyclic alkyl or alkenyl group which may be substituted by a halogen atom, or the like.

Abstract: An optically active carboxylic acid derivative represented by the general formula ##STR1## wherein R represents a normal alkyl group having 1 to 20 carbon atoms, m and n represent 0 or 1 but are not 1 at the same time, X represents a hydrogen or halogen atom, Y represents a hydrogen or fluorine atom, provided that when Y is a hydrogen atom, X is a halogen atom, and that when n is 0, Y is ahydrogen atom, and Q* represents an optically active alkyl or 1-alkoxyethyl group having an asymmetric carbon atom.

Abstract: An optically active carboxylic acid derivative represented by the general formula ##STR1## wherein R represents a normal alkyl group having 1 to 20 carbon atoms, m and n represent 0 or 1 but are not 1 at the same time, X represents a hydrogen or halogen atom, Y represents a hydrogen or fluorine atom, provided that when Y is a hydrogen atom, X is a halogen atom, and that when n is 0, Y is a hydrogen atom, and Q* represents an optically active alkyl or 1-alkoxyethyl group having an asymmetric carbon atom.

Abstract: A liquid crystalline compound represented by formula ##STR1## wherein R denotes an alkyl or alkoxy group having 1 to 20 carbon atoms,m and n are each 0 or 1, provided m and n are not 1 at the same time. ##STR2## X and Y each denote a hydrogen atom, a halogen atom or a nitro group, provided X and Y are not hydrogen atoms at the same time, and Q* denotes an optically active group having an asymmetric carbon atom and a linear or cyclic alkyl or alkenyl group which may be substituted by a halogen atom, or the like.