Abstract The mixed acid (H 2 SO 4-HOAc) catalyzed ring opening of α, β-epoxyketone was the most used method for the preparation of diosphenols, but it seriously suffered from poor yields and tedious workup operations. By using silica gel supported mixed acid (H 2 SO 4- HOAc), a variety of α, β-epoxyketones were converted into the corresponding diosphenols in unprecedented high yields within a few minutes.