Solid-catalyzed synthesis of isomers–free terpinen–4–ol

Terpinen–4–ol is a natural product with wide application in the fragrance and agrochemical industry, currently extracted from tea tree oil or synthesized either base–promoted rearrangement of 1,4–cineol acid–catalyzed hydration limonene. However, these synthetic processes, based on aggressive, unrecoverable homogeneous reagents, are non–selective give significant amounts isomers, which severely complicate make more expensive purification active substance. Here we show isomers–free synthesis terpinen–4–ol, exclusively over solid catalysts such as alumina, nanotitania Pd/C, >60% yield, by selective epoxidation, isomerization terpinolene epoxide allyl alcohol hydrogenation. The can be performed batch flow mode for epoxide. use bare catalyst, here demonstrated, opens new ways quaternary alcohols.