Decahydronaphthalene compound, liquid crystal composition including the compound and liquid crystal display device containing the liquid crystal composition

A compound represented by the formula (1):

• in the formula (1), R1 and R2 are independently alkyl having 1 to 10 carbons, and in the alkyl, arbitrary —CH2— may be replaced by —O—, —S—, —CO— or —SiH2 —, and arbitrary —(CH2)2— may be replaced by —CH═CH— or —C≡C—;
• the ring A and the ring B are independently 1,4-cyclohexylene or 1,4-phenylene, and in the rings, arbitrary one —CH2— may be replaced by —O—, —S—, —CO— or —SiH2— and arbitrary —(CH2)2— may be replaced by —CH═CH—, in the 1,4-phenylene, arbitrary —CH═ may be replaced by —N═, and in the rings, arbitrary hydrogen may be replaced by halogen, —CF3, —CHF2, —CH2F, —OCF3, —OCHF2 or —OCH2 F;
• Z1 and Z2 are independently a single bond or alkylene having 1 to 4 carbons, and in the alkylene, arbitrary —CH2— may be replaced by —O—, —S—, —CO— or —SiH2—, arbitrary —CH2)2— may be replaced by —CH═CH— or —C≡C—, and arbitrary hydrogen may be replaced by halogen;
• and Z3 is —CH2O— or —OCH2—;
• Y1 and Y2 are independently halogen, —CF3, —CHF2, —CH2F, —OCF3, —OCHF2 or —OCH2F;
• and
• m and n are independently 0, 1 or 2, p is 1 or 2, and the sum of m, n and p is 1, 2 or 3.