Etude RMN 13C d'un Dérivé Uniformément Enrichi en 13C. Signe des Valeurs des Constantes de Couplage Observées

The ¹³C NMR parameters of 3-O-acetyl-1,2:5,6-di-O-isopropylidène-α-D-U-¹³C] glucofuranose, used as a sample for analysis in double labelling biosynthetic experiments, have been measured. Homonuclear double resonance experiments ¹³C? {¹³C} at 62.8 MHz have permitted the determination of all the ¹³C? ¹³C coupling constants. By theoretical computation of spectra, in connection with the second order effects existing at 25.2 MHz and 15.08 MHz, the sign of the coupling constants has been determined. The theoretical computation of spectra took into account all the isotopomers and was calculated with the help of a program (adapted from the LAOCOON program) allowing for the weighted addition of the spectra.