Although β-lactam derivatives are well known for their antibiotic activities, 1 recently they have also been used as a synthon for the synthesis of various natural and unnatural products. 2 Ojima has shown the utility of bis-β-lactams for the synthesis 3 of peptides. The synthesis of bis-β-lactams, in general, have been reported by step-wise construction of β-lactam rings. 4 In continuation of our work on synthesis of bis-β-lactams, 4. and 5. we were interested in ...