(2R,3S,4S,5S)-5-(acetoxymethyl)tetrahydrofuran-2,3,4-triyl triacetate → Methyl 1-(2,3,5-Tri-O-acetyl-beta-L-ribofuranosyl)-1,2,4-triazole-3-carboxylate

Beteiligte Stoffe

Reaktionsschritte

A mixture of methyl 1,2,4-triazole-3-carboxylate (0.64 g, 5 mmol), 1,2,3,5-tetra-O-acetyl-β-L-ribofuranose (2) (1.5 g, 4.72 mmol) and bis(p-nitrophenyl)-phosphate (20 mg) were placed in a pear shaped flask and placed in a preheated oil bath at (160-165° C.). The flask was connected to a water aspirator and kept at 160-165° C. (oil bath temperature) under reduced pressure with stirring for 25 min. The reaction mixture was removed, cooled and diluted with EtOAc (150 mL) and sat. NaHCO3 (100 mL). The product was extracted in EtOAc. The organic extract was washed with water (100 mL) and brine (50 mL), dried and evaporated to dryness. The residue that obtained was purified by flash column of silica gel using CHCl3→EtOAc as the eluent. The pure fractions were collected and evaporated to dryness to give 1.2 g (66%) of pure product: 1H NMR (CDCl3) δ2.10 (3s, 9H, 3 COCH3), 3.98 (s, 3H, OCH3), 4.22 (m, 1H), 4.46 (m, 2H), 5.54 (t, 1H), 5.76 (m, 1H), 6.04 (d, 1H, C1′H), and 8.38 (s, 1H, C3H). Anal. Calc. for C15H19N3O9 (385.22): C, 46.75; H, 4.97; N,10.91. Found: C, 46.82; H, 4.57; N=10.71.

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