Deprotection of carboxylic esters of β-lactam homologues. Cleavage of p-methoxybenzyl, diphenylmethyl, and tert-butyl esters effected by a phenolic matrix

p-Methoxybenzyl, diphenylmethyl, and tert-butyl esters were deprotected by gentle heating in phenol. This method of ester cleavage played an important role in β-lactam synthesis. The mechanism of the reaction is believed to involve a proton relay through a hydrogen-bonded phenolic matrix