Using C[Mg]Br, COc1cc(OC)cc(C(=O)CCCCC#C[Si](C)(C)C)c1 to produce COc1cc(OC)cc(C(C)(O)CCCCC#C[Si](C)(C)C)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.