Silicon-29 and carbon-13 n.m.r. studies of organosilicon chemistry. VIII—Assignment of the 29Si and related 1H resonances of trimethylsilylated sugars by deuteration and shift reagent studies

Two techniques were investigated for assigning the ²⁹Si n.m.r. spectra of trimethylsilylated sugars. Specific deuteration, together with selective proton decoupling experiments, has allowed the complete assignment for methyl 2,3,4,6-tetra-O-trimethylsilyl-α-D-glucopyranoside. Double resonance spectra obtained in the presence of a lanthanide shift reagent, Pr(dpm)₃, have enabled the ²⁹Si and ¹H signals for the -SiMe₃, groups of methyl 2,3,4-tri-O-trimethylsilyl-α-D-glucopyranoside, to be linked. A complete and unambiguous assignment of the ²⁹Si spectrum for this molecule was obtained by selective deuteration, thus giving an unequivocal assignment of the –SiMe₃ proton resonances also. Definitive data regarding the effects of Pr(dpm)₃ on the ²⁹Si and ¹H resonances of the various –SiMe₃ groups of methyl 2,3,4-tri-O-trimethylsilyl-α-D-glucopyranoside are therefore available.