2531. NIENBURG, H. (Badische Anilin- u. Soda-Fabrik). [Organic Compounds Containing Oxygen.] German Patent 800,400, Nov. 2, 1950; appl. filed Oct. 2, 1948 (Cl. 12 o-7.03). Chem. Abs., vol. 45, 1951, p. 1625.

Process of preparing organic compounds containing O by reaction of CO and H₂ with diolefins in the presence of hydrogenation catalysts is improved by using dimerized diolefins as reactants. The dimerization is effected by heating the diolefins several hours at 200°-250°. Treating dimerized butadiene thus in presence of a Co-kieselguhr catalyst with a CO-H₂ mixture (1:1) at 120° and 200 atm. for 60-80 min., replacing the CO-H₂ mixture by H₂ (100 atm.), heating the mixture 1 hr. at 120° to decompose the Co carbonyl compounds, and distilling the reaction product in vacuo yields a cyclic singly unsaturated C₉-aldehyde, b.₁₈ 93°-98°. The analogous treatment of dimerized isoprene yields a cyclic C₁₁-aldehyde, colorless oil, b.₁₄ 130°-135°, and small quantities of the corresponding C₁₁-alcohol.

NIENBURG, H. See abs. 1846.