[{"from": "human", "value": "Create a molecule with the structure as the one described. The molecule is an angelica lactone and a butenolide. It is functionally related to a but-3-en-4-olide. It is a tautomer of a beta-angelica lactone."}, {"from": "gpt", "value": "[C][C][=C][C][C][=Branch1][C][=O][O][Ring1][=Branch1]"}]