Using C=CCBr, COC(=O)[C@@H](O)[C@@H](CC(C)C)C(=O)O to produce C=CCOC(=O)[C@H](CC(C)C)[C@H](O)C(=O)OC, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.