The citrus fruit borer (Citripestis sagittiferella) is an important insect pest of citrus fruits in the Mekong Delta of Vietnam. In order to utilization of sex pheromone as tool for a sustainable management, the two sex pheromone components, (E)-14-tetradecenyl acetate (E11-14:OAc) and (Z)-14-tetradecenyl acetate (Z11-14:OAc), were synthesized by using conventional Wittig reaction as key step for the synthetic route. After MOM protection of the hydroxyl group of 11-bromo-1-undecanol, the MOM ether compound was heated with triphenylphosphine to form a phosphonium salt, which was coupled with propanal under the base condition of n-butylLithium to obtain both E and Z-isomers of tetradecen-1-ol MOM ether compound. MOM deprotection and following geometrically isomeric separation by chromatography on 15% AgNO₃ in silica gel produced prospected (E)-14-tetradecen-1-ol (E11-14:OH) and (Z)-14-tetradecen-1-ol (Z11-14:OH) (>98% geometric purity). Following, acetylation of E11-14:OH and Z11-14:OH gave corresponding Z11-14:OAc and Z11-14:OAc