To easily produce trans-cyclohexanecarbaldehydes useful as a synthetic raw material for liquid crystal compounds in high yield by reacting cyclohexanecarbaldehydes rich in cis isomer with a basic compound.
Cyclohexanecarbaldehydes expressed by the formula (R is a 1-15C alkyl, an alkoxy, etc.; X, Y and Z are each covalent bond, 1,2-ethylene bond, etc.; the rings A, B and C are each 1,4-cyclohexylene ring or unsubstituted 1,4-phenylene ring; the ring D is 1,4-cyclohexylene ring) wherein the cis isomer content in the cis/trans isomers on the ring D is >10% are made to react with a basic compound (preferably potassium hydroxide, sodium hydroxide, etc.) to obtain the objective compound containing ≤10% cis isomer in the cis/trans isomers on the ring D of the compound. The reaction is preferably carried out in a reaction solvent such as benzene at -30 to +30°C using 1-5 equivalent of the basic compound based on the substrate. The reaction time is generally 10min to 1hr.
KATO TAKASHI
MATSUI SHUICHI
MIYAZAWA KAZUTOSHI
