Using CCCC1(CC)COc2c(Cc3ccc(C(C)C)cc3)c(C)cc(C)c21 to produce CCC1COc2c(Cc3ccc(C(C)C)cc3)c(C)cc(C)c21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.