Using CCOC(=O)c1ccc([Se]c2cc3c(cc2O)C(C)(C)CCC3(C)C)cc1 to produce CC1(C)CCC(C)(C)c2cc([Se]c3ccc(C(=O)O)cc3)c(O)cc21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.