Synthesis of oligodeoxynucleotides containing 5-(beta-D-glycopyranosyloxymethyl)-2 '-deoxyuridine, a modified nucleoside in the DNA of Trypanosoma Brucei

The synthesis of the recently discovered modified DNA base 5-(beta-D-glucop yranosyloxymethyl)-2'-deoxyuridine (beta-dJ, 1) is,described. TMSOTf mediat ed beta-glucosylation of 5-hydroxymethyl-2'-deoxyuridine (5-HMdU) derivativ e 10 (obtained in 20% from 2'-deoxyuridine) with trichloroacetimidate 12 ga ve dimer 13 in 47% yield. On the other hand, condensation of 12 with N-3-PO M-protected derivative: 20, readily available from thymidine in 48%, afford ed the fully protected nucleoside 22 in 96% yield. The latter compound was converted into phosphoramidite 3 which was applied in the automated solid p hase synthesis of several biological interesting beta-dJ containing DNA fra gments.