Acetic Anhydride → 5'-deoxy TCRB

HRID 2379070Notes

Reaction equation

HRID 2379070 reaction equation
O=[CH:2][C@@H:3]([C@@H:5]([C@@H:7]([CH3:9])[OH:8])[OH:6])[OH:4].[C:10](OC(=O)C)(=O)C.C(O[C@@H]1O[C@H](C)[C@@H](OC(=O)C)[C@H]1OC(=O)C)(=O)C.[Cl:35][C:36]1[NH:37][C:38]2[CH:44]=[C:43]([Cl:45])[C:42]([Cl:46])=[CH:41][C:39]=2[N:40]=1.C(O[C@@H]1O[C@H](COC(=O)C)[C@@H](OC(=O)C)[C@H]1OC(=O)C)(=O)C.[Si](OS(C(F)(F)F)(=O)=O)(C)(C)C>>[CH3:10][CH2:9][C@H:7]1[O:8][C@@H:2]([N:40]2[C:36]([Cl:35])=[N:37][C:38]3[C:39]2=[CH:41][C:42]([Cl:46])=[C:43]([Cl:45])[CH:44]=3)[C@H:3]([OH:4])[C@@H:5]1[OH:6]

Participants

7

Reactant 6

HCID 7918Acetic AnhydrideHCID 65367Trimethylsilyl triflateHCID 830641,2,3,5-Tetraacetyl-beta-D-ribofuranoseHCID 2860092,5,6-Trichloro-1H-benzimidazoleHCID 11821332beta-D-Ribofuranose, 5-deoxy-, 1,2,3-triacetate2×HCID 454897735-deoxy-D-ribose

Product 1

HCID 52730085'-deoxy TCRB

Procedure

Treatment of 205 with dilute acid liberated 5-deoxy-D-ribose which was immediately acetylated in the presence of acetic anhydride, giving an anomeric mixture of 5-deoxy-1,2,3-tri-O-acetyl-β-D-ribofuranose (206). The 5-deoxy-1,2,3-tri-O-acetyl sugar was used as an anomeric mixture for ribosylation of 2,5,6-trichlorobenzimidazole in a manner similar to its 1,2,3,5-tetra-O-acetyl-β-D-ribofuranose counterpart. Thus, silylation of the chlorinated heterocycle (207) was followed by the addition of TMSOTf and 5-deoxy-1,2,3-tri-O-acetyl-β-D-ribofuranose (206) to afford a mixture of the α and β anomers of 2,5,6-trichloro-1-(5'-deoxy-2,3-di-O-acetyl-D-ribofuranosyl)benzimidazole. Separation of these anomers was achieved by chromatography, and deprotection of the β anomer gave the 5'-deoxy TCRB (210).

Workup

  1. customgiving
  2. customto afford
  3. customSeparation of these anomers

Sources & evidence

ORD record
ord-869637c813284382942f0a189b0a8128
Source dataset
uspto-grants-1994_11
Patent number
US05360795

Reaction notes

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