SEARCH Articles Figures Tables 2-Cyclohexenone Allene Cycloadditions Allenes 2 + 2 cycloadditions Allenes cycloaddition Allenes photochemical Allenes photochemical cycloaddition Cycloaddition cyclohexenones Cyclohexenone, 3,4-dimethyladdition to allene Cyclohexenones Photochemical -cycloadditions Photochemical cyclohexenones