Using CC(C)(C)OC(=O)NC1(C(=O)O)CC1, CC1CCC(C)C1O to produce CC1CCC(C)C1OC(=O)C1(NC(=O)OC(C)(C)C)CC1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.