Synthesis and antimicrobial properties of substituted ß-aminoxypropionyl penicillins and cephalosporins

Some β-aminoxypropionyl penicillins (3) and cephalosporins (4 and 5), planned on the basis of the hypothesis that the (methyleneaminoxy)methyl group (>C=NOCH2) could be a "bioisoster" of either aryls or other aromatic groups, were synthesized and assayed for their antimicrobial properties. Compounds 3-5, tested on Gram-positive and Gram-negative bacteria, both sensitive to enzyme inactivation and otherwise, exhibited an activity trend that was not substantially different from that of the corresponding phenylacetamido derivatives taken as terms of comparison.