A facile synthesis of bestatin

Bestatin, an immunomodulator useful in cancer treatment with the structure: N-[(2S,3R)-3-amino-2-hydroxy-4-phenylbutanoyl]-L-leucine, has been synthesized from N-acyl-alpha-aminoacetophenone. This novel method using readily available reagents and mild conditions can be applied to a large scale production of this useful agent. The overall yield of bestatin was 10.5% from N-acetyl-alpha-aminoacetophenone and 7.8% from N-benzoyl-alpha-aminoacetophenone.