SEARCH Articles Figures Tables 1,3-cycloaddition intramolecular 2-pyrone cycloaddition Alder Cycloaddition Cycloadditions, , of 2-pyrones Diels cycloaddition Diels intramolecular Diels pyrone Diels-Alder cycloaddition Diels-Alder cycloadditions Diels-Alder cycloadditions, of 2-pyrones Intramolecular Diels-Alder Intramolecular Diels-Alder cycloaddition