To obtain the subject new liquid-crystalline compound having steep threshold characteristics, having good compatibility with other liquid-crystalline compounds, and having a low viscosity, a proper refractive index anisotropic value and a dielectric constant anisotropic value by introducing a specific structure into the molecule.
A compound of formula I [X1 is H, cyano, etc.; X2 is H, a 1-10C alkyl, etc.; (l), (m), (n), (s), (o) are each 0 or 1; (p), (q) are each 0-5; X3 is a 1-10C alkyl; Z1-Z4 are each mutually independently a covalent bond or a 1-5C alkylene; the rings A1-A6 are each 1,4-phenylene, etc.; B1, B2 are each mutually independently CH=CH or C≡C, wherein B1, B2 are each simultaneously not CH=CH], e.g. 4-toluoyl-4'-(hex-1-en-5-ynyl)bicyclohexane. The compound of formula I is obtained by dibrominating a γ-δ unsaturated aldehyde (formula III) having a mesogen of formula II with tetrabromocarbon in the presence of triphenylphosphine and subsequently treating the reaction product with butyl lithium and then with a halide compound.
TAKEUCHI HIROYUKI
MIYAZAWA KAZUTOSHI
HACHITANI NORIHISA
NAKAGAWA ETSUO
