Using COC(=O)C(=O)Nc1ccc2c(c1)C(C)(C)CCC2(C)C to produce CC1(C)CCC(C)(C)c2cc(NC(=O)C(=O)O)ccc21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.