Zeolite NaY-promoted cyclization of farnesal: a short route to nanaimoal.

The sesquiterpene nanaimoal was synthesized in 21% overall yield and in a biomimetic manner. As a key step, the acid-catalyzed cyclization of farnesal under zeolite NaY confinement conditions was used. The intrazeolite cyclization of farnesal affords as major product a double-bond isomer of nanaimoal, via a novel diastereoselective tandem 1,5-diene cyclization/Prins-type reaction.