Pronounced catalytic activity of magnesium oxide and calcium oxide in isomerization of penta-1,4-diene to penta-1,3-diene

MgO and CaO showed very high activity for the title isomerization compared with ZnO, TiO2 or silica–alumina; the ration of the isomerization activity of penta-1,4-diene to that of but-1-ene was ca. 107 times higher over the alkaline earth metal oxides than over silica–alumina.