Zeolite NaY-Promoted Tandem 1,5-Diene-Carbonyl-Ene Dicyclization of α-Geranyl-Substituted Carbonyl Compounds

The mildly acidic zeolite NaY promotes a tandem dicyclization to a variety of a-geranyl-substituted carbonyl compounds to afford 1,2,3,4,4a,5,6,7-octahydronaphthalen-2-ols in moderate to good yields. In certain cases, the diastereoselection is remarkable. The dicyclization occurs by a 1,5-diene cyclization on the geranyl moiety to form selectively γ-cyclogeranyl-substituted carbonyl compounds, which further cyclize through an intermolecular carbonyl-ene reaction.