213487-06-0Relevant academic research and scientific papers
Stereoselective Preparation of Deuterium-Labeled Sugars: (6R)-(6-2H1)-N-Acetylglucosamine Derivatives
Falcone-Hindley, Margaret L.,Davis, Jeffery T.
, p. 5555 - 5561 (2007/10/03)
The preparation of methyl (6R)-(6-2H1)-2-deoxy-2-N-acetamido-α-D-glucose (8α-d) and methyl (6R)-(6-2H1)-2-deoxy-2-N-acetamido-β-D-glucose (8β-d) is described. The key step in the synthesis was the stereoselective reduction of a C6-aldehydo-GlcNAc derivative with (R)-(+)-Alpine-Borane-d. Reduction of either methyl 6-aldehydo-3,4-di-O-benzyl-α-GlcNAc (6α) or methyl 6-aldehydo-3,4-di-O-benzyl-β-GlcNAc (6β) using (R)-(+)-Alpine-Borane-d in CH2Cl2 was significantly more stereoselective (>15:1 stereoselectivity for both anomers) than was reduction with NaBD4 in MeOH. The absolute stereochemistry at C6 of the deuterated GlcNAc derivatives was determined from 1H NMR analysis of the conformationally locked sugars, methyl (6R)-(6-2H 1)-4,6-O-benzylidene-2-deoxy-2-N-acetamido-α-D-glucose (9α-d) and methyl (6R)-(6-2H 1)-4,6-O-benzylidene-2-deoxy-2-N-acetamido-β-D-glucose (9β-d). Comparison of 3JH5,H6 values and 1H-1H NOEs for the nondeuterated and deuterated benzylidene derivatives showed that reduction with (R)-(+)-Alpine-Borane-d gave the (6R)-(G-2H1) epimer as the major product for both the GlcNAc α and β methyl glycosides. This stereoselective reduction enabled the 1H NMR signals for the prochiral H6 and H6′ protons in a series of GlcNAc derivatives to be assigned.
