Diels-Alder reactions of 1-sulfinyldienes with an endocyclic double bond: The unexpected evolution of the N-methylmaleimide adducts

Article abstract of DOI:10.1016/0957-4166(94)80106-1

(R)-(1E,3E)-2-Cyclohexenyl-1-vinyl-p-tolylsulfoxide 1a and (R)-(1E,3E)-N-methyl-3-[2-(p-tolylsulfinyl) vinyl]-1H-indole 1b reacted with N-methylmaleimide to give Diels-Alder adducts whose in situ evolution through a tandem sulfoxide-sulfenate rearrangemen