Using CCOC(=O)C(=Cc1ccc(OC)cc1OC)C(=O)OCC, CCCCC[Mg]Br to produce CCCCCC(c1ccc(OC)cc1OC)C(C(=O)OCC)C(=O)OCC, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.