Using COC(=O)c1ccc(COc2cccc(CCSC(C)=O)c2C(=O)OC)cc1 to produce O=C(O)c1ccc(COc2cccc(CCS)c2C(=O)O)cc1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.