The synthesis and in vitro testing of structurally novel antibiotics derived from acylnitroso Diels–Alder adducts

The structural similarity between β-lactam antibiotics, such as penicillin, and isoxazolidine-3,5-dicarboxylic acids led to the hypothesis that isoxazolidine-3,5-dicarboxylic acids could be effective analogs of β-lactam antibiotics. The syntheses of relevant isoxazolidine-3,5-dicarboxylic acids from acylnitroso Diels–Alder adducts and subsequent biological testing have shown that these first examples are inhibitors of Escherichia coli X580.