Optically active compound, liquid crystal composition containing the

Abstract

An optically active compound represented by the formula R.sub.1 --A.sub.1 --A.sub.2 --X.sub.1 --A.sub.3 --(CH.sub.2).sub.p --L--A.sub.4 --R.sub.2, in which R.sub.1 is F, CN or straight chain, branched or cyclic alkyl and R.sub.2 is H, F, CH or straight chain or branched alkyl; A.sub.3 is 1,4-phenylene, pyridine-2,5-diyl, pyrimidine-2,5-diyl, pyrazine-2,5-diyl, pyridazine-3,6-diyl, 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl, 1,3-ditiane-2,5-diyl, thiophene-2,5-diyl, thiazole-2,5-diyl, thiaziazole-2,5-diyl, benzoxazole-2,5-diyl, benzoxazole-2,6-diyl, benzothiazole-2,5-diyl, benzothiazole-2,6-diyl, benzofuran-2,5-diyl, benzofuran-2,6-diyl, quinoxaline-2,6-diyl, quinoline-2,6-diyl, 2,6-naphthylene, indane-2,5-diyl, 2-alkylindane-2,5-diyl, indanone-2,6-diyl, 2-alkylindane-2,6-diyl, coumarane-2,5-diyl and 2-alkylcoumarane-2,5-diyl; A.sub.1, A.sub.2 and A.sub.4 are single bond or A.sub.3 ; X.sub.1 ' is a single bond, --COO--, --OCO--, --CH.sub.2 O--, --OCH.sub.2 --, --CH.sub.2 CH.sub.2 --, --CH.dbd.CH-- or --C.tbd.C--; p is an integer from 2 to 20; and L is optically active.