Synthesis and Diels-Alder reactions of N-(tert-butoxycarbonyl)-3-p-tolylsulfinyl-1-benzoquinone-4-imine

Article abstract of DOI:10.1016/0040-4039(96)00491-1

The title compound was synthesized in 3 steps (regioselective sulfenylation, m-CPBA and Pb(OAc)₄ oxidations) from N-Boc-p-anisidine. Its Diels-Alder reactions with cyclopentadiene took place on the double bonds C₂-C₃ or C₅-C₆ depending upon the experimental conditions with total endo-selectivity and high π-facial diastereoselectivity. The cycloaddition with trans-piperylene occurred exclusively on the sulfinylsubstituted dienophilic double bond C₂-C₃.