Studies on the reactivity of azetidin-2-ones in phosphate buffer

Abstract

¹ H NMR (500 MHz) analyses reveal that in phosphate buffer, N-arylsulfonyl β-lactams such as ethyl N-(p-nitrophenylsulfonyl)-2-oxoazetidine-4- carboxylate and (4S)-ethyl 3-ethyl-N-(p-nitrophenylsulfonyl)-2- oxoazetidine-4-carboxylate undergo hydrolysis through (minimally) two mechanisms: via direct hydrolysis and via an unstable acyl phosphate intermediate. The acyl phosphate intermediates can be trapped using hydrazine.