Allyl bromide → HCID 23396873, compound

HRID 881891Notes

Reaction equation

HRID 881891 reaction equation
[Li+].CC([N-][CH:6]([CH3:8])[CH3:7])C.[CH2:9]([O:16][C:17]([CH:19]1[CH2:23][CH2:22][CH2:21][CH2:20]1)=[O:18])[C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1.C(Br)C=C>C1COCC1>[CH2:9]([O:16][C:17]([C:19]1([CH2:8][CH:6]=[CH2:7])[CH2:23][CH2:22][CH2:21][CH2:20]1)=[O:18])[C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1

Participants

5

Reactant 3

HCID 7841Allyl bromideHCID 561517HCID 561517, compoundHCID 2724682Lithium diisopropylamide

Product 1

HCID 23396873HCID 23396873, compound

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-78 °C

Procedure

To a stirred solution of cyclopentanecarboxylic acid (1.14 g, 10 mmol) in DMF (15 mL) is added K2CO3 (2.07 g, 15 mmol) and benzyl bromide (1.71 g, 10 mmol). The suspension is stirred at room temperature for 18 hours. The mixture is quenched with water and extracted with ethyl acetate. The organic layer is washed with water, brine, dried over MgSO4 and filtered. The solvent is removed under reduced pressure and the residue is purified by flash chromatography (heptane:EtOAc, 10:1) to give cyclopentanecarboxylic acid benzyl ester. Next, to a stirred solution of LDA (4 mmol, 2M in Hexane) in THF (8 mL) at −78° C. is added a solution of cyclopentanecarboxylic acid benzyl ester (817 mg, 4 mmol) in THF (3 mL) dropwise. After the addition, the mixture is stirred at −78° C. for 5 hours then allyl bromide (726 mg, 6 mmol) is added dropwise. The mixture is warmed to room temperature during 4 hours then the reaction mixture is quenched with saturated NaHCO3. Magnesium sulfate (2 g) is added and stirred until all the MgSO4 is dissolved. The mixture is extracted with ethyl acetate and the organic layer is washed with water, brine, dried over MgSO4 and filtered. The solvent is removed under reduced pressure and the residue is purified by flash chromatography (hep:EtOAc, 10:1) to give 1-allyl-cyclopentanecarboxylic acid benzyl ester. Next, Ozone is bubbled through a solution of 1-allyl-cyclopentanecarboxylic acid benzyl ester in methylene chloride (15 mL) for 30 min then PS-triphenolphosphine (300 mg) is added and the mixture is stirred at room temperature for 5 hours. The resin is filtered and solvent is removed under reduced pressure. The residue is purified by flash chromatography (heptane:EtOAc, 10:1) to give 1-(2-oxo-ethyl)-cyclopentanecarboxylic acid benzyl ester MS 247.3 (M+1).

Workup

  1. additionAfter the addition
  2. temperatureThe mixture is warmed to room temperature during 4 hours
  3. customthe reaction mixture is quenched with saturated NaHCO3
  4. additionMagnesium sulfate (2 g) is added
  5. stirringstirred until all the MgSO4
  6. dissolutionis dissolved
  7. extractionThe mixture is extracted with ethyl acetate
  8. washthe organic layer is washed with water, brine
  9. dry with materialdried over MgSO4
  10. filtrationfiltered
  11. customThe solvent is removed under reduced pressure
  12. customthe residue is purified by flash chromatography (hep:EtOAc, 10:1)

Sources & evidence

ORD record
ord-2b156417277448c9b54a8bf42f49333d
Source dataset
uspto-grants-2015_03
Patent number
US08993631B2

Reaction notes

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