[{"from": "human", "value": "Please provide possible reagents based on the following chemical reaction. [C][C][=Branch1][C][=O][O][C][C][Branch1][Ring1][C][Br][C][C][C][C][C][Ring1][Branch2]>>[O][C][C][Branch1][Ring1][C][Br][C][C][C][C][C][Ring1][Branch2]"}, {"from": "gpt", "value": "[Br].[C][C][O]"}]