Recently developed mono-cyclic β-lactams are of importance probably due to the exceptional antibacterial spectra and their stability against β-lactamase and their unique nature of the structure. New types of monocyclic β-lactams in which their structures were related to those of penicillins have been synthesized using 2-acetoxyazetidin-2-one and penicillin as starting materials.
Monocyclic β-lactams(10,11) were synthesized by functionalization of 3-amino group, variation of 4-substituent, and N(1)-alkylation. Similarly monocyclic β-lactams(29,30) were also synthesized by displacement of acetoxy group with the alkylthio group.