PROTON AND CARBON-13 NUCLEAR MAGNETIC RESONANCE STUDIES ON METHYL (METHYL D-GALACTOSID)URONATES AND THEIR PER-O-ACETYL DERIVATIVES

Article abstract of DOI:10.1016/S0008-6215(00)80521-2

The 1H- and 13C-n.m.r. spectra of the anomeric methyl (methyl D-galactosid)uronates, as well as the 1H-n.m.r. spectra of their acetyl derivatives, were analyzed.The spectra of the unacetylated D-galactopyranosiduronates showed good correlation with those of the corresponding anomeric D-galactopyranuronic acids and their methyl esters, and with those of the anomeric methyl D-galactopyranosides.From the values of the chemical shifts and coupling constants, it was concluded that the anomeric methyl (methyl D-galactopyranosid)uronates and their corrasponding peracetates are in the ⁴C₁(D) conformation.The chemical shifts in the 13C-n.m.r. spectra show good correlation with those of the methyl D-galactosides.The signals of the furanose derivatives appear at fields lower than those of the corresponding pyranose compounds.