Trifluoroacetic acid → HCID 10594394, compound

Participants

Reaction Steps

While the desired 3',5'-di-O-trityl derivative, compound 2, was only obtained in 10% yield from compound 1, the isomeric 2',5'-ditrityl derivative, compound 3, was obtained in a 30% yield. The fluorination of compound 3 using DAST and pyridine in CH2Cl2 gave 2,5,6-trichloro-1-(2,5-di-O-trityl-3-deoxy-3-fluoro-β-D-xylofuranosyl)benzimidazole (compound 5) in a 71% yield. The fluorination of compound 2 using the same conditions gave 2,5,6-trichloro-1-(3,5-di-O-trityl-2-deoxy-2-fluoro-β-D-arabinofuranosyl)benzimidazole (compound 4) in a 63% yield. Both compounds 4 and 5 were deprotected using 10% CF3COOH in CHCl3 to give good yields of the deprotected nucleosides 2,5,6-trichloro-1-(2-deoxy-2-fluoro-β-D-arabinofuranosyl)benzimidazole (compound 6) and 2,5,6-trichloro-1-(3-deoxy-3-fluoro-β-D-xylofuranosyl)benzimidazole (compound 7), respectively.

Provenance & Evidence