Motivated by these results we were interested in synthesizing novel β-lactam grafted macrocycles. Herein, we describe the synthesis of macrocyclic bis-β-lactams. Incorporation of a β-lactam in a macrocyclic ring could be easily accomplished by Staudinger reaction using the appropriate macrocyclic imine. Thus treatment of α,α′-xylene dibromide 1a with salicylaldehyde and K 2 CO 3 in dry acetone at room temperature afforded dialdehyde 2a (Scheme 1).
