Regioselective Preparation of Cyclohexadienes or Aromatic Nitro Compounds by Diels-Alder Reactions of β-Sulfonylnitroolefins or β-Sulfinylnitroethylene

Article abstract of DOI:10.1021/jo00237a005

β-Sulfonylnitroolefins react with various dienes to give 4-nitro-5-(phenylsulfonyl)cyclohexenes under mild conditions, where the nitro group controls the direction of the addition more effectively than the sulfonyl group.Subsequent treatment of the adducts with Bu3SnH results in the reductive elimination of the nitro and sulfonyl groups to give 1,4-cyclohexadienes.The Diels-Alder reaction of β-sulfinylnitroethylene with dienes and subsequent thermal elimination of sulfenic acid give 1-nitro-1,4-cyclohexadienes, which are readily aromatized to give nitrobenzene derivatives.Thus, β-sulfonylnitroolefins or β-sulfinylnitroethylene is regarded as alkynes or nitroacetylene equivalents for the Diels-Alder reaction, respectively.