Synthesis of Aza-Analogues of the Glycosylated Tyrosine Portion of Mannopeptimycin-E

摘要

Two C4' amido disaccharide analogues of mannopeptimy-cin-E were synthesized via an iterative palladium glycosy-lation sequence. The stereoselective synthesis of the C4' acylated 1,4-α,α-manno, manno-amido disaccharide has been achieved in ten steps from a protected D-tyrosine. The path relies upon a regio- and diastereoselective palladium-catalyzed azide substitution reaction. The competence of the synthesis is demonstrated by the good overall yield (21%) from protected tyrosine.