Captodative% oxy-and 3-(tolylthio)-l-tusyl-2-pyridones la-ld are shown to be reactive as nucleophilic dienes undergoing 2+ 4-cycloadditions with various electrophilic alkenes under sufficiently mild thermal conditions (W100" C) that the initial bicylic lactam adducts can be isolated on gram de in fair to very good yields (23-83%) without loss of an isocyanate from the heteroatom bridge. These bicyclic adducts are formed with complete regiocontrol and ...
