The oxidizing condensation of normal alcohols C-4 to C-12 in the gas phase over Fe3O4 catalyst containing Cr, Si and K oxides was studied. The reactions were carried out in a continuous process at atmospheric pressure. Initially the alcohols undergo dehydrogenation to aldehydes and esters, and at higher temperatures symmetric ketones containing 2n - 1 atoms of carbon in a molecule are formed. A mechanism for the reaction is proposed.