Synthetic studies on carbapenem and penem antibiotics(VI) improved synthesis of (3S,4S)-4-acetoxy-3-phenylacetamido-azetidin-2-one

Penicillin G potassium salt was transformed in high yield to 4-acetoxy-3-phenylacetaminoazetidinone by treatment of mercury acetate, ozonolysis and methanol in sequence.