[{"from": "human", "value": "Synthesize a molecule that matches the given characteristics. The molecule is a butenolide."}, {"from": "gpt", "value": "[C][/C][=Branch1][=C][=C][/C][=C][Branch1][Branch2][C][=Branch1][C][=O][O][\\-Ring1][=Branch1][Cl][/C][=Branch1][C][=O][O]"}]