Tomoko Mochizuki

Ring expansion reactions of penicillin derivatives by rhodium-catalyzed decomposition of diazoketones ??? stereoselective syntheses of eight-membered oxa-β-lactams

Abstract The reaction of penicillin derivatives (1 – 3) with p -nitrobenzyl α-diazoacetoacetate (8) in the presence of a catalytic amount of rhodium acetate afforded the corresponding ring-expanded oxa-derivatives (5 – 7) stereoselectively, in moderate yields.

Novel transformation of penicillin into penem nucleus : synthesis of 2-carboxylpenem derivative

Abstract A novel transformation of 6-aminopenicillanic acid (6-APA) into penem derivative is described.

A short and stereoselective synthesis of the carbapenem antibiotic PS-5

The benzyl ester (3) and p-nitrobenzyl ester (PNB ester)(4) of the antibiotic PS-5 and the bis-protected PS-6 (5) were stereoselectively synthesised by application of the new carbon–carbon bond formation reaction at the C-4-position of 4-acetoxy-3-ethyl- or 4-acetoxy-3-ethyl- or 4-acetoxy-3-isopropyl-azetidin-2-ones [(10) or (11)].