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