Using O=C([O-])[O-], CC(=O)OCC1OC(Oc2ccsc2C=O)C(OC(C)=O)C(OC(C)=O)C1OC(C)=O to produce C=Cc1sccc1OC1OC(COC(C)=O)C(OC(C)=O)C(OC(C)=O)C1OC(C)=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.