A palladium-catalyzed intermolecular cycloaddition of -methylidene--valerolactones with electron-deficient olefins has been developed for the synthesis of spiro[2.4]heptanes with high selectivity through a nucleophilic ring closure to the central carbon of a -allylpalladium intermediate. It was found that the course of the reaction is dependent on the ligand employed, and selective [4 + 2] cycloadditions can also be achieved by the use of a bulky monophosphine ligand.