It was shown that the reaction of -butyl - (diphenylmethylene) glycinate with 2-methyl-3--butyl (dimethyl) silyloxypropanoic acid chloride in CHCl in the presence of CsCO proceeds with the formation of the corresponding β-lactam and an acetylglycine derivative. Under the same conditions, acetyl chloride reacts with -butyl - (diphenylmethylene) glycinate chemoselectively, yielding exclusively -butyl ester of acetylglycine.
Z.R. Valiullina (Wed,) studied this question.