The RuCl3 catalyzed reaction of β-lactams in the presence of acetaldehyde and molecularoxygen in an acid and ethyl acetate under buffer conditions gives the corresponding 4-acyloxy β-lactams highly efficiently.
Osmium-catalyzed oxidation of beta-lactams with peroxides in acetic acid gives the corresponding 4-acetoxy beta-lactams, which are versatile synthetic intermediate of carbapenem antibiotics, in good to excellent yields.
Ruthenium-catalyzed oxidation of amides and lactams with peroxides