An improved synthesis of Karahanaenone

An improved synthesis of the monoterpene cyclic ketone karahanaenone, an ingredient in cosmetics, perfumery, and pest-control agents, is reported. The synthesis uses linalyl acetate as the starting material, which is converted to the epoxide with m-CPBA and submitted to an anhydrous lithium perchlorate catalyzed rearrangement to the corresponding ketone. Hydrolysis and thermolysis of the ketone afford karahanaenone in good yield. The catalyst can be recycled by simple dehydration and reused without affecting the yield for the rearrangement.