Imidazole → HCID 59441458, compound

HRID 391159Notes

Reaction equation

HRID 391159 reaction equation
[CH3:1][O:2][C@H:3]([C@@H:6]([C@H:9]([C@H:12]([CH3:14])[OH:13])[O:10][CH3:11])[O:7][CH3:8])[CH:4]=[O:5].N1C=CN=C1.Cl[Si:21]([C:24]([CH3:27])([CH3:26])[CH3:25])([CH3:23])[CH3:22]>C(Cl)Cl>[C:24]([Si:21]([CH3:23])([CH3:22])[O:5][C@H:4]1[C@H:3]([O:2][CH3:1])[C@H:6]([O:7][CH3:8])[C@@H:9]([O:10][CH3:11])[C@H:12]([CH3:14])[O:13]1)([CH3:27])([CH3:26])[CH3:25]

Participants

5

Reactant 3

HCID 795ImidazoleHCID 28928tert-Butyldimethylsilyl chlorideHCID 14104333HCID 14104333, compound

Product 1

HCID 59441458HCID 59441458, compoundYield 82%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Tri-O-methylrhamnose (20.0 g, 97.0 mmol) was dissolved in CH2Cl2 (400 mL) and treated with imidazole (10.0 g, 147 mmol) and chloro-tert-butyldimethyl silane (TBSCl; 20.0 g, 132 mmol). After 3 days (d), the reaction mixture was partitioned between water (H2O) and CH2Cl2, and the organic layer was washed with brine, dried over sodium sulfate (Na2SO4) and concentrated. The crude residue was further purified by chromatography on silica gel (10-20% ethyl acetate (EtOAc) in petroleum ether as eluant) to give the title compound (12.8 g, 82%) as a clear syrup in a 20:80 α:β ratio. The physical properties of the major β-epimer are: 1H NMR (CDCl3) δ 4.55 (s, 1H), 3.58 (s, 3H), 3.48 (m, 1H), 3.45 (s, 3H), 3.40 (s, 3H), 3.00 (m, 3H), 1.24 (d, J=6.2 Hz, 3H), 0.80 (s, 9H), 0.05 (s, 6H); EIMS m/z 263 ([M-tBu]+, 1), 88 (100).

Workup

  1. customthe reaction mixture was partitioned between water (H2O) and CH2Cl2
  2. washthe organic layer was washed with brine
  3. dry with materialdried over sodium sulfate (Na2SO4)
  4. concentrationconcentrated
  5. customThe crude residue was further purified by chromatography on silica gel (10-20% ethyl acetate (EtOAc) in petroleum ether as eluant)

Sources & evidence

ORD record
ord-8b6bcc22e55740fa9d9b691bfcc08ea5
Source dataset
uspto-grants-2013_02
Patent number
US08383786B2

Reaction notes

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