Optically active ester derivatives, preparation process thereof, liquid crystal materials and a light switching element

摘要

Disclosed herein are optically active carboxylic acid or acid halide compounds of formula III: <IMAGE> (III) Wherein R2 represents an optically active alkyl or alkoxyalkyl group having 3 to 15 carbon atoms optionally substituted by halogen atoms; R' represents a hydroxyl group or a halogen atom; k is 0 or 1; and n represents an integer of 1 to 6.