Stereospecific Synthesis of Methyl 2-Amino-2-deoxy-(6S)-deuterio-αβ-D-glucopyranoside and Methyl 26-Diamino-26-dideoxy-(6R)-deuterio-αβ-D-glucopyranoside: Side Chain Conformations of the 2-Amino-2-deoxy and 26-Diamino-26-Dideoxyglucopyranosides

摘要

The stereospecifically labeled 6-monodeuterio methyl 2,6-diamino-2,6-dideoxy-α- and β-D-glucopyranosides were synthesized with a view to determining their side chain conformations. NMR studies in D2O at pH 5 and pH 11 reveal both anomers to adopt very predominantly the gt conformation consistent with the gauche conformation of 2-aminoethanol and its acetate salt. In contrast, as also revealed with the help of stereospecifically-labelled monodeuterio isotopomers, the methyl 2-amino-2-deoxy-α- and β-D-glucopyranosides are an approximately 1:1 mixture of gg and gt conformers as is found in glucopyranose itself.