Using CC(C)(C)OC(=O)C1CC(C)(C)C(=O)N1C(=O)OC(C)(C)C to produce CC(C)(C)OC(=O)C1CC(C)(C)C(O)N1C(=O)OC(C)(C)C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.