Synthesis of 1′#,2′,3′,4′#,5′,5″-2H6-β-D-ribonucleosides and 1′#, 2′,2″,3′,4′#,5′,5″-2H7-β-D-2′-deoxyribonucleosides for selective suppression of proton resonances in partially-deuterated oligo-DNA, oligo-RNA and in 2,5A core (1H-NMR window)
Raney nickel-2H2O exchange reaction on an epimeric mixture of methyl α/β-D-ribofuranoside [α/β = ∼3:10]1 produced methyl 1#,2,3,4#,5,5′-2H6-α/β-ribofuranoside 2 [97 atom % 2H at C2, C3, C5/5′; ∼85 atom % 2H at C4 (C4#); ∼20 atom % 2H at C1(C1#)] which was obtained in 60 – 80 % yield along with epimeric xylo and arabino by-products. Toluoylation of the crude 2 in dry pyridine and a careful separati