Hydrogen Bromide → HCID 53719156, compound

HRID 1461458Notes

Reaction equation

HRID 1461458 reaction equation
[CH2:1]([O:8][C@H:9]1[C@H:18]([O:19][C:20](=[O:22])[CH3:21])[C@@H:17]([CH2:23][O:24][C:25](=[O:27])[CH3:26])[O:16][CH:11](OC(=O)C)[C@@H:10]1[O:28][C:29](=[O:31])[CH3:30])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[BrH:32]>C(O)(=O)C.COC>[CH2:1]([O:8][C@H:9]1[C@H:18]([O:19][C:20](=[O:22])[CH3:21])[C@@H:17]([CH2:23][O:24][C:25](=[O:27])[CH3:26])[O:16][CH:11]([Br:32])[C@@H:10]1[O:28][C:29](=[O:31])[CH3:30])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

5

Reactant 2

HCID 260Hydrogen BromideHCID 13964977HCID 13964977, compound

Product 1

HCID 53719156HCID 53719156, compound

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolvent2×HCID 8254Dimethyl EtherSolvent

Procedure

To 16 g of compound 4 in 35 mL of acetic acid precooled to 10° C., a solution of hydrogen bromide in acetic acid (50% w/v; 16 mL)-was added slowly. The solution was stirred at 5°-10° C. for 3 hours, diluted with alcohol-free chloroform (250 mL) then washed sequentially with ice water, aqueous sodium hydrogen carbonate, and water, and dried over magnesium sulfate. Removal of the solvent under reduced pressure gave a syrup which was taken up in methyl ether and adsorbed on silica gel (300 g). Elution with light petroleum ether gave 2.5 g of benzyl bromide, and further elution with ether gave a syrup of 3-O-benzyl-2,4,6-tri-O-acetyl-D-glucopyranosyl bromide (5)-which crystallized on cooling. Recrystallization from dry ether gave 12.2 g of needles with m.p. 79° C. and [α]D25 +145 (c=1 in chloroform).

Workup

  1. customprecooled to 10° C.
  2. additionadded slowly
  3. washthen washed sequentially with ice water, aqueous sodium hydrogen carbonate, and water
  4. dry with materialdried over magnesium sulfate
  5. customRemoval of the solvent under reduced pressure
  6. customgave a syrup which
  7. washElution with light petroleum ether
  8. customgave
  9. wash2.5 g of benzyl bromide, and further elution with ether

Sources & evidence

ORD record
ord-4a033bcc2e5e4f488e0c6161d63ce715
Source dataset
uspto-grants-1991_12
Patent number
US05075433

Reaction notes

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