DE2517859

A process for preparing beta , gamma -unsaturated aldehydes which comprises dehydrogenating beta , gamma -unsaturated alcohols in the vapor phase, preferably in the substantial absence of oxygen, using copper having a specific surface area of 0.01 to 1.5 m2/g as a catalyst at a temperature of 150 DEG to 300 DEG C. The beta , gamma -unsaturated aldehydes can be recovered in pure form by distilling the dehydrogenation reaction mixture in the presence of water. The starting beta , gamma -unsaturated alcohols can be prepared by reacting olefins with formaldehyde or a derivative capable of forming formaldehyde at a temperature of 180 DEG to 400 DEG C. in the absence of a solvent or in the presence of a non-aqueous organic solvent after pre-heating said formaldehyde or derivative to a temperature of 85 DEG to 150 DEG C.