Using CCCC1(CCC(C)=O)CCc2cc(OC)c(Cl)c(Cl)c2C1=O to produce CCCC12CCC(=O)C=C1c1c(cc(OC)c(Cl)c1Cl)CC2, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.