The invention relates to the (stereoselective) hydrogenation of carbon-carbon double bonds in compounds having at least one such bond, e.g., isoprenoids, non-cyclic sesquiterpenes, tocomonoenols, tocodienols, tocotrienols or derivatives thereof, as well as to the (stereoselective) hydrogenation of parts/extracts of plant oils containing such tocotrienols or derivatives thereof, in the presence of a chiral Ir complex as the catalyst, whereby preferably one stereoisomer is manufactured in an excess.