Synthesis of Enantiopure a,b-Unsaturated Cyanohydrins using Enzyme Technology.
For years pharmaceutical companies have struggled with the side effects caused by racemic mixtures of pharmaceutical drugs. The most noted example is Thalidomide, a drug marketed widely throughout Europe in the 1960's. The purpose of the drug was to curb morning sickness in pregnant women. Unfortunately, while one enantiomer eased the pain of morning sickness, the other caused mutagenic effects in their unborn children. Using aldehydes, an "enzyme cocktail," consisting of enzyme and citrate buffer of pH 5.5, and HCN solvated by isopropyl ether, a predominately enantiopure cyanohydrin is isolated. The enzyme, oxynitrilase, is extremely robust and affordable, $4.39/bag. When prepared at around 4C, the enzyme is very effective at inducing the (R) enantiomer. Due to the inherent versatility of the a,b-Unsaturated Cyanohydrins and the additional functionality afforded by the substrate, various products can be prepared.
O'Connor, Caitlin, "Synthesis of Enantiopure a,b-Unsaturated Cyanohydrins using Enzyme Technology." (1999). URC Student Scholarship.