Efficient one-pot synthesis of 2-azetidinones from acetic acid derivatives and imines using methoxymethylene-N,N-dimethyliminium salt

A cheap, versatile and convenient method for synthesis of β-lactams using methoxymethylene-N,N-dimethyliminium salt as an acid activator in Staudinger reaction is reported. This method is used for the preparation of monocyclic, spirocyclic, N-alkyl and three-electron-withdrawing group β-lactams. The products are obtained in good to excellent yields.