Liquid crystal compound and process for production thereof, liquid crystal composition, and liquid crystal electrooptical element

A liquid crystal compound represented by the following formula (1):

• R1-(A1)a-Z1-(A2)b-Z2-(A7)e-Z5-A3-CF═CFCF2O-A4-Z3-(A5)c-Z4-(A6)d-R2 (1)
• wherein
• R1 and R2 independently represent hydrogen atom, a halogen atom, —CN, —NCS, —SF5, or an alkyl group containing 1 to 18 carbon atoms, wherein at least one hydrogen atom in the group is optionally substituted with fluorine atom, at least one —CH2— in the group is optionally substituted with ethereal oxygen atom or thioethereal sulfur atom, and at least one —CH2CH2— in the group is optionally substituted with —CH═CH— or —C≡C—,
• A1, A2, A3, A4, A5, A6 and A7 independently represent trans-1,4-cyclohexylene group, 1,4-cyclohexenylene group, 1,3-cyclobutylene group, 1,2-cyclopropylene group, naphthalene-2,6-diyl group, 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, decahydronaphthalene-2,6-diyl group, or 1,4-phenylene group, wherein at least one hydrogen atom in the group is optionally substituted with a halogen atom, one or two ═CH— in the group is optionally substituted with nitrogen atom, and one or two —CH2— in the group is optionally substituted with ethereal oxygen atom or thioethereal sulfur atom,
• Z1, Z2, Z3, Z4, and Z5 independently represent single bond, an alkylene group containing 1 to 4 carbon atoms wherein at least one hydrogen atom in the group is optionally substituted with fluorine atom, and at least one —CH2— in the group is optionally substituted with ethereal oxygen atom or thioethereal sulfur atom, and at least one —CH2CH2— in the group is optionally substituted with —CH═CH— or —C≡C—, and
• a, b, c, d, and e independently represent 0 or 1 with the proviso that 0≦a+b+c+d+e≦3, and
• wherein the compound has a dielectric anisotropy near zero or a negative dielectric anisotropy.