Synthesis and biological activity of γ-lactam analogues of penicillanic and carboapenicillanic acids, and the sodium periodate mediated rearrangement of pyrrolidine- 2, 3-diones are described. 1, 3-Dipolar addition of cyclic nitrone (6) and methyl acrylate afforded the bicyclic adducts (7a) and (7b). Reductive cleavage of the NO bond and subsequent cyclisation of a regioisomer (11a) gave the γ-lactams (12a) and (12b) in a ...
