[{"from": "human", "value": "Use the given information to create a molecule that fulfills the desired purpose. The molecule is a dicarboxylic acid monoester that is succinic acid in which one of the carboxy groups has been converted to its methyl ester. It is a dicarboxylic acid monoester and a hemisuccinate."}, {"from": "gpt", "value": "[C][O][C][=Branch1][C][=O][C][C][C][=Branch1][C][=O][O]"}]