Ethyl 2-oxovalerate → 4-HYDROXY-4-METHYL-5-HEXENOIC ACID gamma LACTONE

HRID 2378368Notes

Reaction equation

HRID 2378368 reaction equation
O=[C:2]([CH2:8]CC)[C:3]([O:5][CH2:6][CH3:7])=[O:4].[CH:11]([Mg]Br)=[CH2:12]>C1COCC1>[CH3:7][C:6]1([CH:11]=[CH2:12])[O:5][C:3](=[O:4])[CH2:2][CH2:8]1

Participants

4

Reactant 2

HCID 123521Ethyl 2-oxovalerateHCID 178418507HCID 178418507, compound

Product 1

HCID 1025504-HYDROXY-4-METHYL-5-HEXENOIC ACID gamma LACTONEYield 53.6%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of ethyl 2-ketopentanoate (10 mL, 71 mmol) in 100 mL of THF at −78° C. was added dropwise a solution of 1.0 M vinyl magnesium bromide (80 mL, 80 mmol). After completion of the addition, the mixture was stirred for two more hours, the cooling bath was removed and the mixture was gradually warmed to ambient temperature. After the removal of the most of the solvent, the residue was poured to 2N HCl aqueous solution, extracted with ethyl acetate and dried over MgSO4 Purification by lash column chromatography on silica gel with DCM as elute afforded 4.80 grams of 5-methyl-5-vinyl-dihydro-furan-2-one. 1H-NMR (300 MHz, CDCl3) δ (ppm): 5.824-5.917 (dd, 1H); 5.29 (d, 1H); 5.13 (d, 1H); 2.50-2.56 m, (2H); 2.07-2.18 (m, 2H); 1.48 (s, 3H).

Workup

  1. additionAfter completion of the addition
  2. customthe cooling bath was removed
  3. customAfter the removal of the most of the solvent
  4. additionthe residue was poured to 2N HCl aqueous solution
  5. extractionextracted with ethyl acetate
  6. dry with materialdried over MgSO4 Purification by lash column chromatography on silica gel with DCM
  7. washas elute

Sources & evidence

ORD record
ord-94582e3d002140a8a5daefe156b4e422
Source dataset
uspto-grants-2008_12
Patent number
US07470798B2

Reaction notes

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