Total Synthesis of Native 5,7-Diacetylpseudaminic Acid from N-Acetylneuraminic Acid

The pseudaminic acids are a family of 5,7-diamino-3,5,7,9-tetradeoxynonulosonic acids that are functional components of flagellin and pili proteins within clinically relevant Gram-negative bacteria. Herein, we describe the total synthesis of the most common pseudaminic acid, 5,7-diacetylpseudaminic acid, from N-acetylneuraminic acid. The divergent nature of the route reported here provides a robust and versatile means to access other members of the family, together with analogues, for probing the functional role of the pseudaminic acids and pseudaminic acid derived proteins in the future.