Silane, bromotriethyl- → alpha-Acetobromogalactose

HRID 1772999Notes

Reaction equation

HRID 1772999 reaction equation
C(O[C@@H:5]1[O:22][C@H:21]([CH2:23][O:24][C:25](=[O:27])[CH3:26])[C@H:16]([O:17][C:18](=[O:20])[CH3:19])[C@H:11]([O:12][C:13](=[O:15])[CH3:14])[C@H:6]1[O:7][C:8](=[O:10])[CH3:9])(=O)C.[Br:28][Si](CC)(CC)CC.C(=O)([O-])O.[Na+]>ClCCl.[Bi](Br)(Br)Br>[C:8]([O:7][C@@H:6]1[C@@H:11]([O:12][C:13](=[O:15])[CH3:14])[C@@H:16]([O:17][C:18](=[O:20])[CH3:19])[C@@H:21]([CH2:23][O:24][C:25](=[O:27])[CH3:26])[O:22][C@@H:5]1[Br:28])(=[O:10])[CH3:9]

Participants

6

Reactant 3

HCID 70680Silane, bromotriethyl-HCID 94752beta-D-Galactose pentaacetateHCID 516892Sodium Bicarbonate

Product 1

HCID 2734143alpha-AcetobromogalactoseYield 100.7%

Reagents, catalysts & solvents 2

HCID 82232bismuth(III) bromideCatalystHCID 6344DichloromethaneSolvent

Procedure

β-D-Galactose pentaacetate (5.00 g, 12.8 mmol) and bismuth(III) bromide (287 mg, 640 μmol) were dissolved in dichloromethane (25 mL), the solution was added with bromotriethylsilane (6.76 mL, 51.2 mmol), and the mixture was stirred at room temperature for 3 hours under an argon atmosphere. The reaction mixture was poured into aqueous saturated sodium hydrogencarbonate cooled on ice, then the mixture was extracted with dichloromethane, and the organic layer was washed with brine. The organic layer was dried over sodium sulfate, and the solvent was removed to obtain 2,3,4,6-tetra-O-acetyl-α-D-galactopyranosyl bromide (5.30 g, quantitative).

Workup

  1. temperaturecooled on ice
  2. extractionthe mixture was extracted with dichloromethane
  3. washthe organic layer was washed with brine
  4. dry with materialThe organic layer was dried over sodium sulfate
  5. customthe solvent was removed

Sources & evidence

ORD record
ord-dc0815c0857f49c2ac0db63c74bd1076
Source dataset
uspto-grants-2016_02
Patent number
US09250232B2

Reaction notes

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