Hexamethyldisilazane → 6-Amino-1-(2,3,5-tri-O-benzoyl-beta-D-ribofuranosyl)cytosine

Beteiligte Stoffe

Reaktionsschritte

A mixture of 6-aminocytosine (1.00 g, 5.71 mmol) and HMDS (10 mL) was refluxed for 3 h and concentrated to give a solid, which was dissolved in anhydrous CH2Cl2 (15 mL). To the solution were added 1-O-acetyl-2,3,5-tri-O-benzoyl-D-ribose (1.92 g, 3.81 mmol) and TMSOTf (1.66 mL, 8.59 mmol) at 0° C., and the mixture was stirred at room temp. for 12 h and poured into saturated sodium bicarbonate solution with vigorous stirring. The mixture was extracted with CHCl3 (150 mL×2), the combined extracts dried (Na2SO4) and concentrated in vacuo, and the residue purified by silica gel column chromatography (CHCl3:MeOH=30:1) to give compound 21 (1.18 g, 54%) as a white foam. 1H NMR (DMSO-d6) δ 7.97-7.40 (m, 15H), 6.18 (s, 1H), 6.18 (m, 3H), 5.10 (s, 1H), 4.65 (m, 3H).

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