Abstract: A 2H-5,6-optically active dihydropyran derivative represented by the general formula (I) or (I'): ##STR1## wherein Rf represents a fluoroalkyl group having 1 or 2 carbon atoms; a liquid crystal composition and a liquid crystal device comprising the derivative; and a racemic mixture comprising at least one type of the derivative. The derivative is a novel compound which exhibits the liquid crystal property by itself or can be used as an excellent dopant providing a high speed response to a composition comprising it even when the compound does not exhibit the liquid crystal property by itself. The derivative also exhibits a large spontaneous polarization.

Abstract: A 2H-5,6-optically active dihydropyran derivative represented by the general formula (I) or (I'): ##STR1## wherein Rf represents a fluoroalkyl group having 1 or 2 carbon atoms; a liquid crystal composition and a liquid crystal device comprising the derivative; and a racemic mixture comprising at least one type of the derivative. The derivative is a novel compound which exhibits the liquid crystal property by itself or can be used as an excellent dopant providing a high speed response to a composition comprising it even when the compound does not exhibit the liquid crystal property by itself. The derivative also exhibits a large spontaneous polarization.

Abstract: An optically active tetrahydropyran derivative represented by one of the following general formulae, a liquid crystal composition containing the derivative, and a liquid crystal device containing the composition are disclosed. The optically active tetrahydropyran derivative is a novel compound which is chemically stable, causes no coloring, has excellent optical stability, and shows a large spontaneous polarization and a quick response. The optically active tetrahydropyran derivative can show a more excellent quick response when it is used in a composition, and is useful as a component in a ferroelectric liquid crystal which induces a large spontaneous polarization.

Abstract: There are disclosed a novel optically active tetrahydropyrane derivatives (for example, (2R,5R,6R)-tetrahydro-6-trifluoromethyl-2-hexyloxy-5-(4"-hexyloxybiphenyl) -4'-carbonyloxy)pyrane; (2S,5R,6R)-tetrahydro-6-trifluoromethyl-2-hexyloxy-5-(4"-hexyloxybiphenyl) -4'-carbonyloxy)pyrane, etc. may be mentioned.) represented by the formula (I): ##STR1## or (I'): ##STR2## wherein symbols in the formula are as described in the specification, which is available as a liquid crystal material used for a display device or an electro-optic device, a liquid crystal composition and a liquid crystal device containing the same.The optically active tetrahydropyrane derivative of the present invention can improve high speed response particularly when it is made a composition, and is available as a compositional component for a ferroelectric liquid crystal which induces a large spontaneous polarization.

Abstract: A ferroelectric liquid crystal mixture containing at least one chiral compound, having negative dielectric anisotropy and exhibiting a chiral smectic C phase includes at least one compound selected from the group consisting of a compound represented by the following general Formula I and a compound represented by the following general Formula II: ##STR1## where R.sup.1 and R.sup.2 are the same or different straight-chain or branched chain alkyl groups having 1 to 15 carbon atoms; X.sup.1 is a single bond, --O--, --COO--, or --OCO--; X.sup.2 is --O-- or --OCO--; Y is --COO-- or --CH.sub.2 O--; A and B are independently a group including a six membered ring which can be substituted by halogen, a cyano group, a lower alkoxy group, or a fluorine-containing alkyl group; and Z is a single bond, --COO--, or --OCO--.

Abstract: There are disclosed a novel optically active tetrahydropyrane derivatives (for example, (2R,5R,6R)-tetrahydro-6-trifluoromethyl-2-hexyloxy-5-(4"-hexyloxybiphenyl) -4'-carbonyloxy)pyrane; (2S,5R,6R)-tetrahydro-6-trifluoromethyl-2-hexyloxy-5-(4"-hexyloxybiphenyl) -4'-carbonyloxy)pyrane, etc. may be mentioned.) represented by the formula (I): ##STR1## or (I'): ##STR2## wherein symbols in the formula are as described in the specification, which is available as a liquid crystal material used for a display device or an electro-optic device, a liquid crystal composition and a liquid crystal device containing the same.The optically active tetrahydropyrane derivative of the present invention can improve high speed response particularly when it is made a composition, and is available as a compositional component for a ferroelectric liquid crystal which induces a large spontaneous polarization.

Abstract: There is disclosed an optically active fluorine-containing compound represented by the general formula (I) ##STR1## wherein Rf is a fluoroalkyl group having 1 or 2 carbon atoms; R.sup.1, R.sup.2 and R.sup.3, independently of one another, are each a hydrogen atom, a straight or branched chain alkyl group having 1 to 15 carbon atoms, an alkenyl group having 2 to 15 carbon atoms or an aralkyl group having 7 to 10 carbon atoms; and * is an asymmetric carbon atom. The above compound has a fluoroalkyl group with a remarkable electron-attracting property at the asymmetric carbon atom in the tetrahydropyran ring. It is exemplified by tetrahydro-6-trifluoromethyl-2-hexyloxy-4-methyl-5-hydroxypyran and expected to find a wide variety of useful applications as raw materials for an enzyme inhibitor, a bioactive substance, a carcinostatic, a ferroelectric liquid crystal, etc.