Metal Ion Binding by Dipeptides: Structure of the Product Generated in "Aspartame" Hydrolysis, Sodium cyclo(L-α-Aspartyl-L-phenylalanine) Tetrahydrate, Na*4H2O
Ester cleavage of aspartame (L-α-aspartyl-L-phenylalanine methyl ester, 1) by equimolar quantities of NaOH is accompanied by intramolecular cyclisation to sodium 3-benzyl-6-(carboxylatomethyl)-2,5-dioxopiperazine (2).The solid-state structure of the cryst