Hydrogen Bromide → Tri-O-acetyl-D-glucal

HRID 1584631Notes

Reaction equation

HRID 1584631 reaction equation
O=[CH:2][C@@H:3]([C@H:5]([C@@H:7]([C@@H:9]([CH2:11][OH:12])[OH:10])[OH:8])[OH:6])O.C(O[C:17](=[O:19])[CH3:18])(=O)C.Br.[C:21]([OH:24])(=O)[CH3:22].[C:25]([O-])(=[O:27])[CH3:26].[Na+].Br>[O-]S([O-])(=O)=O.[Cu+2].[Zn].C(O)(=O)C.O>[C:25]([O:6][C@H:5]1[C@H:7]([O:8][C:21](=[O:24])[CH3:22])[C@@H:9]([CH2:11][O:12][C:17](=[O:19])[CH3:18])[O:10][CH:2]=[CH:3]1)(=[O:27])[CH3:26]

Participants

10

Reactant 5

HCID 260Hydrogen BromideHCID 7918Acetic AnhydrideHCID 107526(2R,3S,4R,5R)-2,3,4,5,6-pentahydroxyhexanalHCID 517045Sodium Acetate2×HCID 21893785Acetic Acid Mixture with Hydrobromic Acid2×

Product 1

HCID 688303Tri-O-acetyl-D-glucalYield 98%

Reagents, catalysts & solvents 4

HCID 23994ZincCatalystHCID 24462Copper SulfateCatalystHCID 176Acetic AcidSolvent2×HCID 962WaterSolvent

Procedure

Glucose (1.000 g) was suspended in a solution of acetic acid (10 mL) and acetic anhydride (3.606 g, 7.0 equiv) and 1.000 g 31% HBr/acetic acid solution added. The reaction mixture was allowed to stir for 1 h, after which 9.000 g more 31% HBr/acetic acid solution (total of 7.7 equiv HBr) was added and allowed to stir overnight. Sodium acetate was then added (2.700 g) to neutralized the excess HBr, and the reaction mixture was added to a suspension containing pulverized CuSO4 ·5H2O (0.315 g), zinc (12.600 g), water (10 mL), sodium acetate (9.450 g), and acetic acid (5 mL) and the resultant reaction mixture was stirred vigorously for 1.5 h. The solution was then filtered and the solid washed with ethyl acetate (100 mL) and water (100 mL). The organic layer of the filtrate was then washed with NaHCO3 (100 mL) and brine (50 mL), dried (Na2SO4), filtered and the solvent removed under reduced pressure to provide tri-O-acetyl-D-glucal (1.350 g, 98%) as a colorless oil free of impurities as judged by 1H NMR.

Workup

  1. additionadded
  2. stirringto stir overnight
  3. additionthe reaction mixture was added to a suspension
  4. additioncontaining
  5. customthe resultant reaction mixture
  6. stirringwas stirred vigorously for 1.5 h
  7. filtrationThe solution was then filtered
  8. washthe solid washed with ethyl acetate (100 mL) and water (100 mL)
  9. washThe organic layer of the filtrate was then washed with NaHCO3 (100 mL) and brine (50 mL)
  10. dry with materialdried (Na2SO4)
  11. filtrationfiltered
  12. customthe solvent removed under reduced pressure

Sources & evidence

ORD record
ord-126f04cdea02416ba2d0a0c3ce9e82fc
Source dataset
uspto-grants-1999_08
Patent number
US05932709

Reaction notes

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