Theoretical Calculations of β‐Lactam Antibiotics. Part VI. AM1 calculations of alkaline hydrolysis of clavulanic acid

摘要: The gas-phase basic hydrolysis of clavulanic acid (a) was studied by using the AM1 semi-empirical method. results obtained show that hydroxyethylidene side chain at C(2) is pivotal to stability different reaction products involved. with an open oxazolidine ring are more stable than those a closed fused β-lactam ring. This behaviour differs from penicillins and cephalosporins where most degradation intact thiazolidine or dihydrothiazine ring, respectively, chemical reactivity relative could explain disparate latter two types compound towards β-lactamases. Once acyl-enzyme intermediate has been formed, it can evolve cleavage form difficult deacylate compound.