Synthesis of Oligodeoxynucleotides Containing 5‐(β‐D‐Glucopyranosyloxymethyl)‐2′‐deoxyuridine, a Modified Nucleoside in the DNA of Trypanosoma Brucei
The synthesis of the recently discovered modified DNA base 5-(β-D-glucopyranosyloxymethyl)-2′-deoxyuridine (β-dJ, 1) is described. TMSOTf mediated β-glucosylation of 5-hydroxymethyl-2′-deoxyuridine (5-HMdU) derivative 10 (obtained in 20% from 2′-deoxyuridine) with trichloroacetimidate 12 gave dimer 13 in 47% yield. On the other hand, condensation of 12with N3-POM-protected derivative 20, readily available from thymidine in 48%, afforded the fully protected nucleoside 22 in 96% yield. The latter compound was converted into phosphoramidite 3 which was applied in the automated solid phase synthesis of several biological interesting β-dJ containing DNA fragments.