[{"from": "human", "value": "Create a molecule that satisfies the conditions outlined in the description. The molecule is a beta-angelica lactone. It is an enantiomer of a (R)-5-methylfuran-2(5H)-one."}, {"from": "gpt", "value": "[C][C@H1][C][=C][C][=Branch1][C][=O][O][Ring1][=Branch1]"}]