Synthesis, NMR, and conformational studies of methyl α-d-mannopyranoside 2-, 3-, 4-, and 6-monophosphates

The syntheses of methyl α-d-mannopyranoside 2-, 3-4-, and 6-phosphate disodium salts are described. 1H, 13C, and 31P NMR spectra of the four monophosphates were recorded, fully assigned, and compared to nonphosphorylated methyl α-d-mannopyranoside in order to obtain chemical shift changes due to phosphorylation. The magnitude of these changes are up to 0.45 ppm for 1H and 3.0 ppm for 13C NMR spectra. The preferred orientation of the phosphate group in the four compounds was also calculated.