Synthetic Uses of Open-Chain Analogues of Reissert Compounds

Article abstract of DOI:10.1021/jo01295a027

Open-chain analogues, 2, of Reissert compounds are readily obtained by reaction of cyanohydrins with primary amines, the resulting aminonitriles, 1, then being acylated.Hydrofluoroborate salts, 3, of 2 are prepared by reaction with fluoroboric acid in glacial acetic acid.The salts, 3, undergo 1,3-dipolar addition reactions with reactive alkynes to give substituted pyrroles and with ethyl acrylate to give a different type of substituted pyrrole, the initial step in this instance being a Diels-Alder reaction.The open-chain Reissert analogues 2 also undergo base-catalyzed reactions, such as alkylation to provide compounds 22, which, in turn, undergo cleavage reactions in ethanolic alkali to give ketones 23.A conjugate addition reaction of the anion 18 to methyl acrylate to give, after some subsequent steps, a substituted pyrrole, 9, has also been demonstrated. α-Anilino ketones 27 result when the anion 18 is caused to react with aldehydes, the initial reaction mixtures being subjected to subsequent alkaline hydrolysis.Finally, N-benzyl Reissert analogues have been found to give desoxybenzoins plus benzonitriles on treatment with sodium hydride in tetrahydrofuran.