The Addition of Diethyl Malonate into Aldehydes Catalyzed by Oxynitrilase in Defatted Almond Meal

Abstract

Defatted almond meal, which contains oxynit-rilase, has been used as a catalyst for the produc-tion of aromatic and aliphatic (R)-cyanohydrins. Oxynitrilase, which is also known as mandeloni-trile lyase (or hydroxynitrile lyase, Hnls), catalyzes the reversible formation of cyanohydrins from HCN and aldehydes or ketones (Scheme 1).1 The reverse reaction occurs because HCN acts as a defense sys-tem against microbial attack.2 In 1908, oxynitrilase was used as a catalyst in asymmetric synthesis.3 Now more than 3000 plants are known to contain this enzyme.4,5 Oxynitrilase have received considerable attention in industry for the synthesis of chiral compounds, which are formed from the stereospecific addition of HCN to alde