Chiral Hydroxymethyl Groups: 1H NMR Assignments of the Prochiral C-5'Protons of 2'-Deoxyribonucleosides

Article abstract of DOI:10.1002/mrc.1260280409

2'-Deoxyadenosine, 2'-deoxycytidine, 2'-deoxyguanosine and 2'-deoxyuridine were prepared with stereoselective deuteration at C-5' and used to assign the prochiral C-5' protons in 300 MHz 1H NMR spectra obtained in 2H2O.In all cases, the more shielded C-5'proton was found to be the pro-R proton.From these assignments, C-4'-C-5' rotamer populations were determined using three previously published methods based on the spin couplings, ³J(H-4',H-5'R) and ³J(H-4',H-5'S), and the errors associated with these methods were assessed.The effects of base structure, furanose and N-glycoside bond conformation on the relative populations of hydroxymethyl rotamers in nucleosides are discussed.