The sex pheromone of grapholitha molesta 8(Z/E)-dodecen-1-ol acetate (6) was synthesized by using oleic acids as the raw material. 1,8(Z)-Heptadecadiene (2) was obtained from the decarbonylation reaction of oleic acid (1) in the presence of palladium complexes catalyst. Selective hydroboration and oxidation of 2 by Ca(BH 4) 2/H 2O 2 system gave 8(Z)-heptadecen-1-ol (3), which then was acetylized by treatment with Ac 2O/pyridine to afford 8(Z)-heptadecen-ol acetate(4). The compound 4 was ozonized to form the key intermediate 8-acetoxyoctanal (5), then compound 5 was coupled with the Wittig regents to obtain the title compound 8(Z/E)dodecen-1-ol acetate (6), Z/E molar ratio is 25∶75. The overall yield was 45%. The structures of all the compounds were confirmed by IR, MS and NMR spectra.
The reaction mechanism of decarbonylation of aliphatic acids to 1-alkenes by Pd(PPh3)2Cl2, which involues formation ofmixed anhydride, oxidation addition, insertion and antiinsertion, displacement of ligands, is suggested according to theexperimental finding and primary reaction of Pd(II) complexs catalyst.
