A one-pot synthesis for the preparation of 1,4-disubstituted
2-oxoazetidine-3-carboxylic acid amides was developed. 5-[(N-substituted-amino)(hydroxy)methylene] Meldrum’s
acids act as a source of ketenes that react with aldimines in boiling
toluene to give β-lactams with a retro-amide side chain.
lactams - cycloaddition - amides - ketenes - Meldrum’s acid