Method for selective preparation of cis isomers of ethylenically unsaturated compounds

摘要

A novel method for the selective preparation of the cis isomer of a disubstituted ethylenically unsaturated compound is proposed in which a disubstituted acetylenically unsaturated compound is partially hydrogenated in the presence of, in place of a conventional Lindlar catalyst or a combination of a Lindlar catalyst with an amine, a palladium catalyst borne on an alumina carrier in combination with water and a hydroxide or a basic salt of an alkali metal or an alkaline earth metal. The inventive method is advantageous over conventional methods by the unnecessity of the use of an amine compound which is definitely undesirable when the product is directed to the application in perfumery and by the easiness in handling of the catalyst which can be easily separated from the reaction mixture after completion of the reaction.