A compound represented by formula (1-1) or (1-2) is provided. For example, R1 and R2 are independently hydrogen, alkyl having 1 to 10 carbons or alkoxy having 1 to 9 carbons; the ring A1, the ring A2, the ring A3, the ring A4, the ring A5 and the ring A6 are independently 1,4-cyclohexylene or 1,4-phenylene; a, b, c, d, e and f are independently 0 or 1, and the sum of a, b, c, d, e and f is 2; and g, h, i, j, k and l are independently 0 or 1, and the sum of g, h, i, j, k and l is 2.