Using O, COC(=O)C(C)c1ccc2c(c1)C(C(=O)OC)C(=O)c1ccccc1S2 to produce CC(C(=O)O)c1ccc2c(c1)C(=O)Cc1ccccc1S2, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.