[{"from": "human", "value": "Design a molecule that meets the criteria outlined in the description. The molecule is a lactone."}, {"from": "gpt", "value": "[C][C][Branch2][Ring1][Ring1][C][C][C][=Branch1][C][=O][O][C][Ring1][#Branch1][Branch1][=Branch1][C][C@H1][Ring1][Branch2][O][C][C]"}]