Orthoester derivative, liquid crystal composition and liquid crystal display device

A liquid crystal composition containing a first component and a second component, wherein the first component is at least one compound selected from the compounds represented by formula (1):

• wherein, in the formula, R1 is alkyl having 1 to 10 carbons, and in the alkyl, at least one of —CH2— may be replaced by —O—, at least one of —(CH2)2— may be replaced by —CH═CH—, and at least one of hydrogen may be replaced by halogen;
• ring A1, ring A2, ring A3, ring A4, ring A5 and ring A6 are independently 1,4-cyclohexylene or 1,4-phenylene, at least one of —CH2— in the 1,4-cyclohexylene may be replaced by —O—, at least one of —(CH2)2— in the 1,4-cyclohexylene may be replaced by —CH═CH—, at least one of —CH═ in the 1,4-phenylene may be replaced by —N═, and at least one of hydrogen in the 1,4-phenylene may be replaced by halogen;
• Z1, Z2, Z3, Z4, Z5, Z6 and Z7 are independently a single bond, —(CH2)2—, —COO—, —OCO—, —CF2O—, —OCF2— or —CH═CH—;
• X1 is fluorine, —CF3 or —OCF3;
• Y1 and Y2 are independently hydrogen or fluorine;
• i, j, k, n, p and q are independently 0 or 1;
• and a sum of i, j, k, m, n, p and q is 2, 3 or 4.