[{"from": "human", "value": "Describe this molecule. [C][C][Branch1][Ring1][C][=O][C][=Branch1][C][=O][O]"}, {"from": "gpt", "value": "The molecule is the 2-methyl-3-oxo derivative of propanoic acid. It is a 3-oxo monocarboxylic acid and an aldehyde. It is functionally related to a propionic acid. It is a conjugate acid of a 2-methyl-3-oxopropanoate."}]