[{"from": "human", "value": "Create a molecule that satisfies the conditions outlined in the description. The molecule is a medium-chain fatty acid and a member of allenes."}, {"from": "gpt", "value": "[C][C][=Branch1][C][=O][/C][=C][/CH1+1][/C][=C][/C][=C][/C][=Branch1][C][=O][O-1]"}]