[{"from": "human", "value": "Please propose potential reagents that might have been utilized in the provided chemical reaction. [C][O][C][=Branch1][C][=O][C][C][C][C][C][=O]>>[O][=C][C][C][C][C][C][=Branch1][C][=O][O]"}, {"from": "gpt", "value": "[C][O].[O].[O][=S][=Branch1][C][=O][Branch1][C][O][O]"}]