l,l,l',l'-tetroxide (3). These products can be isolated from the dark brown reaction mixture by fractional crystallization from benzene or by column chromatography on alumina with acetone as eluting agent. The absence of an amino-olefinic grouping in (2) and (3) follows from their stability towards aqueous acids and excess methanesulfonyl chloride/triethylamine. This also excludes the possibility that the monoadduct is a precursor of the diadduct (3). li ( 3 ) (CzHdzN 18 60 80-82 139-141 Piperidino I I : 13 1 113-115 I 149-151 Morpholino 157-158 181-182
The monosulfones (2) have infrared absorptions at 1120, 1270, and 1315 cm-1 (S02) and a t 700 and 1650 cm-1 (cisolefin). Their N M R spectra exhibit signals for two olefinic protons at T = 4.1-4.3, a ring proton on the amino-substituted carbon at T = 5.9-6.2, and four protons adjacent to the SO2 group at T = 6.2-6.5 and 6.8-6.9. The compounds absorb 1 mole of hydrogen over palladium, and afterwards no olefinic double bond can be detected. The chemical and spectroscopic properties of the disulfones (3) indicate that they contain no C=C double bond. We consider that the formation of the monosulfones ( 2) is due to a 1,4-cycloaddition of the amino diene ( I ) onto sulfene, HzC=S02, formed in situ, and that the disulfones (3) arise by a 3,4cycloaddition followed by a 1,2-cycloaddition.