Abstract: p-Isopropylbenzoic acid is synthesized from β-pinene, through a three-step sequence of oxidation, ring-opening and dehydrogenation. The overall yield is 29.9%. The synthesis of the goal is a new approach. Besides, the conditions of each reaction step are studied. The dehydrogenation of dihydrocumic acid has been discussed emphatically. The optimum conditions of dehydrogenation are 7.5% Pd/C as catalyst, p-isopropylmethylbenzene as solvent, refluxing time 2 h. The yield is 89%.

Key words: β-pinene, nopinic acid, dihydrocumic acid, p-isopropylbenzoic acid