Olefins are reacted with CO and H2 in the presence of a catalyst consisting of Fe on an inert support. Aldehydes are formed in the 1st stage of the process and then these are catalytically hydrogenated to the corresponding secondary alcohols. The synthesis catalyst consists of 20-40% Fe, 0.3-3.0% Cu, 50-75% kieselguhr and 0.05-1.0% K2CO3. Diisobutylene is converted at 135° and at 210 atm. pressure with CO and H2. The product has the following constants: Carbonyl number 257, hydroxyl number 41, saponification number 13, and acid number 0.7. It is hydrogenated with Ni on a support at 177° and 189 atm. pressure. The same constants for the hydrogenation products are 186, 1, 32, and 0.2, respectively.