Synthesis of γ-Oxo γ-Aryl and γ-Aryl α-Amino Acids from Aromatic Aldehydes and Serine



γ-Oxo α-amino acids and γ-aryl α-amino acids are compounds with very interesting biological properties and are active components of many drug molecules. Oxo amino acids are also used as synthetic precursors for a number of unnatural amino acids and amino alcohols. We report a very efficient synthesis of such compounds through the coupling of aromatic dithianes, prepared from aromatic aldehydes and an iodide derivative of serine. The dithiane groups in compounds thus obtained can be either hydrolyzed or reduced to generate 4-oxo-4-aryl or 4-aryl 2-amino butanol derivatives, respectively, which, on further transformations, can be converted into the title compounds. Starting with L-serine provides the corresponding D-amino acids with complete enantiopurity. The reported method is economically viable and complements the existing methods, which rely largely on cross-coupling reactions.