[{"from": "human", "value": "Create a molecule that satisfies the conditions outlined in the description. The molecule is a butynal which has a monosubstituted triple bond. It has a role as a mouse metabolite. It is a terminal acetylenic compound, an alpha-CH2-containing aldehyde and a butynal."}, {"from": "gpt", "value": "[C][#C][C][C][=O]"}]