rac-Ethyl rel-(2R,3R,4S)-4-hy-droxy-1,2-dimethyl-5-oxopyrrolidine-3-carboxyl-ate.

The asymmetric unit of the title compound, C9H15NO4, consists of a functionalized pyrrolidine ring having an envelope conformation, synthesized as an ethyl ester. The mol-ecule has three chiral centres and crystallized as a racemic mixture. In the crystal, mol-ecules are linked by pairwise O-H⋯O bonds, generating dimers with twofold rotational symmetry.