Diels-Alder Reactions of Vinyl Derivatives of Five-Membered Monoheterocyclic Compounds

Article abstract of DOI:10.1021/jo00163a011

Vinylpyrroles having electron-withdrawing substituents react with dienophiles to give <4 + 2> ? adducts while the furan and thiophene analogues do not.The difference in reactivity among the monoheterocycles can be explained in terms of the greater electron-releasing ability of the nitrogen atom in the pyrrole.The s-cis conformation of the (1H-pyrrol-2-yl)maleate derivatives appears to be an important factor in their undergoing the cycloaddition reaction.