pathway to acylpyrrolidinones via a nitro-Mannich reaction, followed by the intramolecular 1,3-dipolar cycloaddition of a nitrile oxide to an alkyne was developed. The syntheses of a leucine-derived tetramicacid and natural tetramide (+)-laccarin were achieved in five steps using aldehydes, 2-alkynamides and nitromethane as the carbon sources.