Stereospecific synthesis of methyl 2-amino-2-deoxy-(6S)-deuterio-alpha,beta-D-glucopyranoside and methyl 2,6-diamino-2,6-dideoxy-(6R)deuterio-alpha,beta-D-glucopyranoside: Side chain conformations of the 2amino-2-deoxy and 2,6-diamino-2,6-dideoxyglucopyranosides

摘要

The stereospecifically labeled 6-monodeuterio methyl 2,6-diamino-2,6-dideoxy-alpha- and beta- o-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-alpha- and beta- D-glucopyranosides are an approximately 1:1 mixture of gg and gt conformers as is found in glucopyranose itself. (C) 2017 Elsevier Ltd. All rights reserved.