A liquid crystalline compound represented by general formula (1), ##STR211## where R.sup.1 and Y.sup.1 independently represent an alkyl group having 1 to 20 carbon atoms, a hydrogen atom, a halogen atom, a cyano group, a cyanate group an isocyano group, or an isothiocyanate group, in which one or more nonadjacent methylene groups in said alkyl group may be substituted by an oxygen atom, a sulfur atom, a nitrogen atom, --C.ident.C--, a dialkylsilylene group, a monoalkylsilylene group, a silylene group, or a vinylene group, and one or more hydrogen atoms in the alkyl group may be substituted by a fluorine atom or a chlorine atom;
- X.sup.1, X.sup.2, X.sup.3, and X.sup.4 independently represent a single bond, --(CH.sub.2).sub.2 --, --C.ident.C--, --COO--, --OCO--, CH.sub.2 O--, --OCH.sub.2 --, --(CH.sub.2).sub.4 --, --(CH.sub.2).sub.3 O--, --O(CH.sub.2).sub.3 --, --CH.dbd.CHCH.sub.2 CH.sub.2 --, --CH.sub.2 CH.dbd.CHCH.sub.2 --, --CH.sub.2 CH.sub.2 CH.dbd.CH--, --CH.dbd.CHCH.dbd.CH--, --CF.sub.2 O--, --OCF.sub.2 --, --CH.dbd.CHCH.sub.2 O--, --OCH.sub.2 CH.dbd.CH--, --CF.dbd.CF--, --CH.sub.2 CF.sub.2 --, --CF.sub.2 CH.sub.2 --, --(CF.sub.2).sub.2 --, --(CF.sub.2).sub.4 --, --(CH.sub.2).sub.2 COO--, --OCO(CH.sub.2).sub.2 --, --CH.dbd.CHCOO--, --OCOCH.dbd.CH--, --CH.dbd.CHC.ident.C-- or --C.tbd.CCH.dbd.CH--;
- ring A.sup.1, ring A.sup.2, ring A.sup.3, ring A.sup.4, and ring A.sup.5 independently represent trans-cyclohexane-1,4-diyl, cyclohexa-1-ene-1,4-diyl, 1,4-phenylene, bicyclo[1,1,1]pentane-1,3-diyl, 6,6-difluorotetrahydropyran-1,5-diyl, 6,6-difluoro-2,3-dihydro-6H-pyran-2,5-diyl, or 6-fluroro-3,4-diydro-2H-pyran-2,5-diyl, wherein carbon atoms constituting the ring of trans-cyclohexane-1,4-diyl, cyclohexa-1-ene-1,4-diyl or 1,4-phenylene may be substituted by nitrogen atoms, oxygen atoms, or sulfur atoms, and hydrogen atoms on the ring may be substituted by halogen atoms or cyano groups, but at least one of said rings A.sup.1, A.sup.2, A.sup.3, A.sup.4, and A.sup.5 is 6,6-difluorotetrahydropyran-2,5-diyl, 6,6-difluoro-2,3-dihydro-6H-pyran-2,5-diyl, or 6-fluroro-3,4-dihydro-2H-pyran-2,5-diyl and a heterocyclic ring is not directly connected to bicyclo[1,1,1]pentane-1,3-diyl, 6,6-difluorotetrahydropyran-2,5-kiyl, 6,6-difluoro-2,3-diyhro-6H-pyran-2,5-diyl or 6-fluoro-3,4-dihydro-2H-pyra-2,5-diyl;
- l, m, n, o, and p are independently 0 or 1, but 4.gtoreq.l+m+n+o+p.gtoreq.2;
- and any atom of this compound may be substituted by an isotope thereof.