Studies of Carbohydrate Derivatives by Nuclear Magnetic Double Resonance. Part VI. The Identification of 13C Chemical Shifts of Methyl Resonances via the 1H–{13C} INDOR Technique

The 13C chemical shifts of acetate- and methoxyl-methyl substituents of several pyranose carbohydrate derivatives have been measured by the 1H–{13C} INDOR technique. The chemical shifts (δ13C) of anomeric methoxyl-methyl resonances fall into two groups: for α-anomers (axial substituent), δ13C = 55.12–56.63 p.p.m.; for β-anomers (equatorial substituent), δ13C = 56.63–8.69 p.p.m. O-Acetyl-methyl shifts fall between 20.54–20.72 p.p.m. and N-acetyl-methyl shifts were detected between 22.98–23.08 p.p.m.