Lipase-catalyzed transformations as key-steps in the large-scale preparation of vitamins

In this account, scope and limitations for the application of hydrolytic enzymes (lipases) to large-scale syntheses of economically important bulk products (vitamins) are discussed. In three case studies, biocatalytic alternatives were compared to “classical” chemical processes. While in the first example (pantolactone) the lipase-catalyzed kinetic resolution by esterification of the hydroxy-γ-lactone did not provide superior results for the overall-process, the synthetic strategies for the preparation of key-intermediates for fat-soluble vitamins could be improved significantly by using selected robust, immobilized lipases under optimized conditions. Regioselective mono-acetylation of a primary-secondary diol for a Vitamin A synthesis as well as mono-saponification of a hydroquinone-diacetate for a route to Vitamin E provided the monoacetylated key-intermediates in excellent yields and selectivities (generally >97%). Examples of laboratory procedures and continuous production on kilogram-scale are given. In consideration of environmental, technical, and economical aspects of modern industrial syntheses, these processes are, therefore, superior to classical (de)acetylation procedures.