Knowledge of side chain conformation of saccharides is an essential element in the investigation of their biological properties. However, in the 2-amino and 2,6-diamino series it has not proven possible to rigorously assign the pro-R and pro-S diastereotopic hydrogens by nOe methods and as such the unambiguous description of the side chain conformation has not been possible. We report the stereospecific synthesis of monolabeled 6S-deuterio methyl 2-amino-2-deoxy-α- and β-D-glucopyranoside and 6R-duterio methyl 2,6-diamino-2,6-dideoxy-α- and β-D-glucopyranosides with a view to determining their side chain conformations. NMR studies in D2O at pH 5 reveal both anomers of 2,6-diamino 2,6-dideoxy series to adopt very predominantly the gt conformation consistent with the gauche conformation of 2-aminoethanol in aqueous acid. In contrast, as also revealed with the help of stereospecifically-labelled monodeuterio iostopomers, the series of 2-amino-2-deoxy are an approximately 1:1 mixture of gg and gt conformers as is found in glucopyranose itself.

Stereospecific deuteration of C6 position on the 2-amino-2-deoxy and 2,6-diamino-2,6-dideoxy glucopyranosides derivatives for their side chain conformational analysis

254th National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.