 By installing an electron-withdrawing substituent such as a methoxy group at the C2 position, the reduction of substituted cyclohexanones begins to favor equatorial attack.This is because the axial C-O bond is a worse electron donor than a C–C bond, so axial attack is less favored.Cieplak also demonstrated this effect by introducing electron withdrawing substituents on C3, which decrease the electron-donating capability of the ring C–C bond and therefore disfavor equatorial attack, which is antiperiplanar to this bond.