Synthesis of 3′-Thioribouridine, 3′-Thioribocytidine, and Their Phosphoramidites

Abstract

3′-Thio-3′-deoxyribonucleosides (U and C) have been synthesized via Vorbruggen-type glycosylation with 3-S-benzoyl-5-O-toluoyl-1,2-O-diacetylfuranose, which was obtained from 1,2-O-isopropylidene-5-O-toluoyl-3-O-trifluoromethanesulfonyl-α-D-xylofuranose. 3′-Thio-3′-deoxyuridine has been converted to its phosphoramidite.

Notes

Every new compound was characterized by ¹H- and ¹³C-NMR, and either a satisfictory molecular weight from high resolution mass spectrometry or a satisfactory elemental analysis was obtained. For the final thiouridine phosphoramidite 14 ³¹ P-NMR (90 MHz, in CDCI₃, using 85% H₃PO₄ as external standard): = 168.6, 157.4; Anal. calcd for C₄₅H₆₁N₄O₈PSSi: C, 61.64; H, 6.96; N, 6.39; S, 3.65. Found: C, 61.38; H, 6.95; N, 6.62; S, 3.49.