Abstract In order to determine whether the condensing activity of reduced copper is affected by the mode of preparation of the catalyst, the condensation of isopropyl alcohol to isobutyl methyl ketone, diisobutyl ketone, and isobutylmethylcarbinol was studied with catalysts prepared in different ways. It was found that the copper catalyst obtained by the hydrogen treatment of the oxide prepared from copper nitrate and an excess of sodium hydroxide was the most suitable catalyst for the condensation of isopropyl alcohol to isobutyl methyl ketone and diisobutyl ketone, and that the copper catalyst prepared with potassium carbonate was the most suitable catalyst for the dehydrogenation of isopropyl alcohol to acetone with no side reaction.