process for the production of c - and c - cycloalkenen with a ring by selective hydrogenation of the corresponding nichtkonjugierten polyolefins with a palladiumkatalysator

摘要

The partial hydrogenation of cyclic polyolefins to mono-olefins is effected in the presence of water and a palladium or palladium compound catalyst. The catalyst may be a divalent salt of palladium or a p -bonded olefin complex in solution or on a support in an amount of 0.1-5% based on hydrocarbon and calculated as metal. The amount of water may be 50-150% by weight of hydrocarbon and there may also be present up to 40% by weight of the water of a polar water-miscible solvent, e.g. dimethylformamide, dimethyl sulphoxide or piperidine. Inert solvents may also be present. Reaction is effected at 25-150 DEG C. and 1-100 atmospheres for a time until the hydrogen consumption is the theoretical requirement. The reduction of cyclododecatriene and cyclooctadiene are exemplified.