Synthesis of cyclic sulfonamides by reaction of <Emphasis Type="Italic">N</Emphasis>-sulfinyl-3-(trifluoromethyl)aniline with norbornenes

N-Sulfinyl-3-(trifluoromethyl)aniline reacted with bicyclo2.2.1]hept-2-ene and bicyclo2.2.1]-hepta-2,5-diene to give the corresponding Diels?Alder adducts which were oxidized to 8-trifluoromethyl-2,3,4,4a,6,10b-hexahydro-5λ⁶-1,4-methanodibenzoc,e]1,2]thiazine-5,5(1H)-diones. The cycloaddition occurred predominantly with participation of the S=N–C¹=C⁶ fragment of N-sulfinyl-3-(trifluoromethyl)aniline and exclusively at the endo side of bicyclo2.2.1]heptenes.