Oxidation of clavulanic acid and a ready synthesis of the 7-oxo-4-oxa-1-azabicyclo[3.2.0]hept-2-ene ring system
Abstract
Pyridinium chlorochromate oxidation of benzyl clavulanate gave the Z- and E-aldehydes (3) and (4), whereas attempted Pfitzner–Moffat oxidation resulted in the formation of the diene (5).