[{"from": "human", "value": "Synthesize a molecule that matches the given characteristics. The molecule is the simplest member of the class of pyrrolidin-2-ones, consisting of pyrrolidine in which the hydrogens at position 2 are replaced by an oxo group. The lactam arising by the formal intramolecular condensation of the amino and carboxy groups of gamma-aminobutyric acid (GABA). It has a role as a polar solvent and a metabolite."}, {"from": "gpt", "value": "[C][C][C][=Branch1][C][=O][N][C][Ring1][=Branch1]"}]