A 2H-5,6-optically active dihydropyran derivative represented by the general formula (I) or (I'): ##STR1## wherein Rf represents a fluoroalkyl group having 1 or 2 carbon atoms; a liquid crystal composition and a liquid crystal device comprising the derivative; and a racemic mixture comprising at least one type of the derivative. The derivative is a novel compound which exhibits the liquid crystal property by itself or can be used as an excellent dopant providing a high speed response to a composition comprising it even when the compound does not exhibit the liquid crystal property by itself. The derivative also exhibits a large spontaneous polarization.
一种具有光学活性的二氢
吡喃衍
生物A 2H-5,6,其
化学式为(I)或(I'):##STR1## 其中Rf代表具有1或2个碳原子的氟烷基;一种液晶组合物和一种液晶器件,包括该衍
生物;以及包含至少一种该衍
生物的外消旋混合物。该衍
生物是一种新化合物,它本身表现出液晶性质,或者即使该化合物本身不表现出液晶性质,也可以用作提供高速响应的优秀掺杂剂。该衍
生物还表现出大的自发极化。