Synthesis and Application of Carbohydrate-Derived Morpholine Amino Acids

Abstract

The synthesis of series of diversely functionalized ε-morpholine amino acids (MAAs, 5a−h) starting from an ε-sugar amino acid and following a two-step oxidative glycol cleavage/reductive amination strategy, is described. In an alternative synthetic scheme, diastereoisomerically pure δ-MAAs (12a,b) were obtained. Oligopeptides containing MAAs were prepared either by direct incorporation of a MAA building block or by subjecting a fully assembled SAA-containing peptide to the two-step glycol cleavage/reductive amination procedure.