A simple oxime–nitrone isomerisation and intramolecular nitrone-cycloaddition reaction of 3-(alk-2-enylamino)propionaldehyde oximes

Abstract

3-(Alk-2-enylamino)-2,2-dimethylpropionaldehyde oximes 3 underwent thermally induced 1,3-dipolar cycloaddition under mild conditions leading to isoxazolo[4,3-c]pyridine derivatives 4. The methyl groups at the 2-position and the alkenylamino nitrogen in oximes 3 should facilitate the cycloaddition due to restriction of the conformational flexibility of the reaction sites and promotion of the isomerisation to NH-nitrone intermediate, respectively.