Hydrogenation of cyclic unsaturated compounds

In a process for hydrogenation, with elemental hydrogen gas in the presence of a hydrogenation catalyst, under hydrogenation conditions, of a cyclic unsaturated compound having a hydroxyl group projecting from an asymmetric center of the ring and an olefinic carbon-to-carbon double bond which when saturated in the hydrogenation process creates in additional asymmetric center in the ring, the improvement for obtaining increased stereoselectivity by increasing the addition of said hydrogen to that side of the olefinic bond on the same side of the compound molecule as said hydroxyl group, wherein said hydrogenation is conducted with a nickel hydrogenation catalyst that has an effective fraction of its reactive surfaces inactivated by treating said catalyst with an effective amount of a modifier selected from the group consisting of:

• an inorganic salt of a metal from Groups I through VIII, Periods 4 through 7 of the Periodic Table, of the Rare Earths of the Periodic Table, and of aluminum;
• organic halides;
• hydrogen halides;
• and halo compounds or arsenic and boron.