1. It was found that a modified skeletal Co catalyst is active in the asymmetric synthesis ofβ-hydroxybutyrate. The highest optical yield reaches 8.1% at a modification pH of 3.6. 2. The asymmetric yield depends on the temperature of leaching the starting Co-Al alloy. 3. The dependence of the optical purity of the reaction product on the pH of modifying the skeletal catalyst bears a complex character.