Bubb, William A. 2003 Concepts in Magnetic Resonance, Part A 19A(1) 1–19. DOI 10.1002/cmr.a.10080
“A value of 170 Hz for 1JC-1,H-1 indicates an equatorial proton at C-1 (e.g., α-D-glucose), while 1JC-1,H-1 160 Hz indicates an axial proton (e.g., β-D-glucose); a number of mechanisms that rationalize this difference in terms of stereoelectronic factors have been advanced (74).”
74. Tvaroska I, Taravel FR. 1995. Carbon–proton coupling constants in the conformational analysis of sugar molecules. Adv Carbohydr Chem Biochem 51:15–61.
The configuration of the anomeric carbon is obviously a key question in structure determination of a glycoside. Besides the difference above, there are also differences in 3JHH between carbons-1 and 2 of glucosides and I would imagine other glycosides. The chemical shift of H-1 is different for the two anomers of free glucose. Yet, I thought that the difference in one bond coupling magnitudes was worth highlighting because it was surprising, at least to me. With respect to the glucose group within lactose, the chemical shift of the C-1 carbon differs by about 4 ppm.