Reactivity and the mechanism of reactions of β-sultams with Nucleophiles

Ethane-1,2-sultam has a pKa of 12.12 ± 0.06 at 30 C and its rate of alkaline hydrolysis shows a pH-dependence
reflecting this so that the observed pseudo first-order rate constant at pHs above the pKa are pH independent. There
is no evidence of neighbouring group participation in the hydrolysis of either N-α-carboxybenzylethane-1,2-sultam
or N-(hydroxyaminocarbonylmethyl)-2-benzylethane-1,2-sultam. Oxyanions, but not amines or thiols, react with
N-benzoylethane-1,2-sultam in water by a nucleophilic ring opening reaction confirmed by product analysis and
kinetic solvent isotope effects. A Brønsted plot for this reaction has two distinct correlations with βnuc = 0.52 and
0.65 for weak and strong bases, respectively, although a statistically corrected plot may indicate a single correlation.