SEARCH Articles Figures Tables 2,3-quinodimethane, Diels-Alder reactions Diels-Alder reaction quinodimethanes Diels-Alder reactions precursor Quinodimethane Quinodimethanes Quinodimethanes precursors Reaction sulfonates Reactions precursors Sulfonated Diels-Alder Sulfonation reaction Sulfones, acetoxyphenylo-quinodimethane precursor