Using CC12CCC3(CC1=CCCC2C=O)SCCS3, COc1cc(Br)cc(OC)c1OC to produce COc1cc(C(O)C2CCC=C3CC4(CCC32C)SCCS4)cc(OC)c1OC, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.