Synthesis and conformational analysis of methyl 3-amino-2,3-dideoxyhexopyranosiduronic acids, new sugar amino acids, and their diglycotides

The synthesis of methyl 3-azido- and 3-amino-2,3-dideoxyhexopyranosiduronic acids and their methyl esters with the -α,β-d-arabino-, -α,β-d-ribo, and -α,β-l-lyxo configurations is presented. The conformations of the synthesized sugar amino acids and their precursors are discussed on the basis of 1H NMR data. The influence of the 5-carboxyl group on the pyranose ring conformation is assessed, and the bonding of the monosugar amino acids into dimeric glycotides, using conventional solution-phase peptide syntheses, is reported.