Monobactams. Preparation of (S)-3-Amino-2-oxoazetidine-1-sulfonic Acids from L-α-Amino-β-hydroxy Acids via Their Hydroxamic Esters

Article abstract of DOI:10.1021/jo00147a024

The cyclization of the O-methylhydroxamates 13-15 afforded excellent yields of the 1-methoxyazetidinones 16-18.Reductive cleavage of the methoxy group gave N-1-unsubstituted azetidinones 9, 19, and 20 which were sulfonated and deprotected, yielding zwitterions 29-31.These materials serve as general intermediates for the preparation of a large variety of monobactam antimicrobial agents.