Notably the products were isolated as single regioisomers, with Michael addition having occurred at the more electrophilic of the two alkenes in the presumed intermediate cyclohexadienone. Hydroxynaphthalenes could also be cyclised effectively, leading to polycyclic tetralone derivatives 2o-r. Finally, cyclisation of an 8-hydroxytetrahydroquinolinecontaining substrate gave the tetracycle enamine 2s in good yield. We also investigated the behaviour of some alternative substrates (Scheme 1). The activation of the ortho-substituted phenol 3 with PIFA under the standard reaction conditions did not produce a regioisomeric spirocycle to products 2, but rather gave the fused tricyclic urea 4 in 19%. The precise order We also examined the potential to employ nucleophiles other than ureas in the Michael addition step, and prepared βamidoester 5. Oxidation to the spirocyclodienone occurred smoothly but the expected conjugate addition did not occur under the mildly acidic reaction conditions; instead, the cyclisation could be effected as a separate step under basic conditions using cesium carbonate. The product was again formed as a single regioisomer via attack at the lesssubstituted alkene, and as a single diastereomer whose stereochemistry was determined by X-ray crystallography (Supporting Information).