3-(5-Oxo-L-prolyl)-L-thiazolidine-4-carboxylic acid

The molecular structure of the title compound, C 9 H 12 N 2 O 4 S, with (2S,4S) absolute configuration, is characterized by the cisoid geometry of the carboxylic acid residue and by the presence of two different disordered conformations of the thiazolidine moiety