Electrophilic cyclization of α- and β-geranyl acetates by mercury(II) trifluoroacetate

Electrophilic cyclization of β-geranyl acetate promoted by mercury(II) trifluoroacetate leads to mixtures of α- and γ-5αH-cyclogeranyl acetate derivatives and 6α-hydroxy-5αH-and 6α-hydroxy-5βH-cyclogeranyl acetate derivatives mercurated at the C-3 atom. The ratio of the unsaturated and hydroxymercurated products depends on the reaction conditions. α-Geranyl acetate reacts with mercury(II) trifluoroacetate to give a mixture of 6α-hydroxy-5αH-and 6α-hydroxy-5βH-geranyl acetates, mercurated at C-9, with an equatorial mercurated methylene group at C-4. The mercury-containing groups in mercurated cyclogeranyl derivatives can easily be reduced or replaced by an oxygen-containing functional group; this constitutes a convenient route to polyfunctional cyclogeranyl derivatives that are difficult to obtain.