Chemical and biological potential of new azetidinone derivatives.

Beta-Lactam compounds are really “evergreen” molecules. Beside bicyclic beta-lactam substrates such as penicillins, cephalosporins, and carbapenems, monocyclic compounds (azetidinones) emerged for their interesting and variegated biological activities. We developed the synthesis of a new class of monocyclic beta-lactam derivatives, 4-alkyliden-azetidinones, characterized by a C=C bond on the C-4 position of the ring.4-Alkyliden-azetidinones proved to be interesting scaffold for antibiotics against resistant bacteria and effective enzymatic inhibitors against Human Leukocyte Elastase (HLE) and matrix metallo-proteases (MMPs), and as antiaggregating agents.4 In exploring their use as synthons we observed that the C=C double bond in 4-alkyliden-azetidinones revealed an unexpected characteristic of low reactivity towards addition reactions of electrophiles or nucleophiles, whereas we succeeded in an unexpected oxidative substitution of vinylic hydrogen or halodecarboxylation reaction which led to the synthesis of mono and di-vinylhalides of 4-alkylidene-azetidinones. Our interest in the design of new beta lactam compounds with specific biological activities recently allowed us to extend our strategies to the synthesis of new monocyclic derivatives with specific inhibitory potency against integrins and histone deacetylase enzymes (HDAC).