Using O=C([O-])[O-], CCC1(CC)c2cc(OC(=O)OC(C)(C)C)ccc2C[C@@H](S)[C@@H]1NC(=O)OC(C)(C)C to produce CCC1(CC)c2cc(OC(=O)OC(C)(C)C)ccc2C[C@@H](SC)[C@@H]1NC(=O)OC(C)(C)C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.