Starting from the natural Penicillins G and V, a series of monocyclic p-lactams B were prepared, functionalized at N(1) by an acetyl residue and at C(3) and C(4), respectively, by an acylamino side-chain and a sulfone substituent in a cis-stereochemical relationship. The TAL and PIV prodrugs exhibited weak antibacterial activity in vitro.
Marchand-Brynaert, J. (1997). Synthesis and antibacterial activity of monocyclic beta-lactams related to cephalosporin and penicillin sulfones. Societes Chimiques Belges. Bulletin, 106(9-10), 585-604. https://hdl.handle.net/2078.5/73779 (Original work published 1997)