Bestatin: Three decades of synthetic strategies

Bestatin (ubenimex) is a dipeptide that can treat a variety of diseases. Over the last thirty years synthetic chemists have developed an assortment of routes to optically pure (-)-Bestatin. Many strategies include the use of pure starting materials like sugars and amino acids. In addition, the utilization of chiral auxiliary groups have been implemented to achieve an increase in stereoselectivity and to simplify the purification process. Lastly, asymmetric catalysis using enzymes or inorganic catalysts has also been used to afford the desired stereochemistry. This review will cover 23 synthetic strategies to (-)-Bestatin through the year 2005.