Abstract: Synthesis of camphoric anhydride was carried out using α-pinene as the starting material. 2-chlorocamphane was prepared by addition and isomerization of α-pinene and dry hydrogen chloride, and it was further eliminated HCl in alkaline condition to obtain bornylene. Camphoric anhydride was finally obtained by oxidation of bornylene with KMnO₄ in mixed acetic anhydride-water solvent. Influences of solvent systems, volume ratio of acetic anhydride and water, the amount of KMnO₄, reaction temperature and reaction time on the oxidation of bornylene were examined in detail. The suitable oxidation conditions were determined as follows: KMnO₄ used as the oxidant for oxidizing bornylene into camphoric anhydride, KMnO₄/bornylene molar ratio 2.5:1, acetic anhydride/H₂O mixture with a volume ratio of 3:1 used as the solvent, solvent/bornylene ratio 20:1(mL:g), reaction temperature 40℃ and reaction time 4 h. The yield of camphoric anhydride was over 94% under the aforesaid conditions. Its chemical structure was determined with GC-MS, FT-IR, ¹H NMR, and ¹³C NMR spectra.

Key words: α-pinene, camphoric anhydride, 2-chlorocamphane, bornylene, oxidation