SEARCH Articles Figures Tables 5-endo-trig Cyclization 4+2]Cycloaddition reactions 8-Endoe endo, cyclization Cyclization 2 + 2] Cycloaddition Cyclization 2+2]Cycloaddition reactions Cyclization Cycloadditions Cyclization reaction 2+2] cycloadditions Cyclization reactions Cyclizations 2+2+2]Cycloaddition Cyclizations 5-endo Endo-cyclization reactions