Celebrating 50 years of the Bílik reaction: history and present

Abstract Epimerization reactions catalyzed by transition metals have changed the previous methods used in the synthesis of rare carbohydrates. In July 2024, we commemorated the 95th anniversary of the birth of Prof. Vojtech Bílik, the discoverer of a new reaction in the synthesis of rare carbohydrates. Over fifty years ago, many sugars were generally prepared by the Lobry de Bruyn–Alberda van Ekenstein isomerization reaction, which was the simplest method for a long period. However, this approach was not very efficient and the epimeric aldose was usually obtained in lower yield than the ketose. A new methodology introduced by Bílik in the 1970′s showed that the synthesis of epimeric aldoses mediated by the molybdenum Mo(VI) catalyst could significantly improve the preparation of rare aldoses without undesirable side reactions. Due to the simplicity and high efficiency of the reaction, the stereospecific Mo(VI)-catalyzed transformation of aldoses was used for preparative purposes and soon gained international recognition. The Mo(VI)-catalyzed epimerization reaction of aldoses was named after its discoverer, and it is the only reaction in the chemical literature of carbohydrates named after a Slovak scientist. On this anniversary, we take the opportunity to summarize the scientific achievements in this field of research.