Ethyl isobutyrate → Ethyl 2,2-dimethylpent-4-ynoate

HRID 1917595Notes

Reaction equation

HRID 1917595 reaction equation
[Li+].[CH3:2]C([N-]C(C)C)C.[CH2:9]1[CH2:14][CH2:13][CH2:12][CH2:11]C1.[C:15]([O:20][CH2:21][CH3:22])(=[O:19])C(C)C.C(Br)C#C.[NH4+].[Cl-]>C1COCC1>[CH3:2][C:12]([CH3:11])([CH2:13][C:14]#[CH:9])[C:15]([O:20][CH2:21][CH3:22])=[O:19]

Participants

7

Reactant 5

HCID 7342Ethyl isobutyrateHCID 7842Propargyl bromideHCID 8078CyclohexaneHCID 25517Ammonium ChlorideHCID 2724682Lithium diisopropylamide

Product 1

HCID 14459632Ethyl 2,2-dimethylpent-4-ynoateYield 95%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-78 °C

Procedure

To a cold (−78° C.) solution of THF (100 ml) is added a 1.5M solution of LDA in cyclohexane (260 mL, 390 mmol) via cannulation, followed by the addition of ethyl isobutyrate. The mixture is allowed to stir at −78° C. for 1 hr then propargyl bromide is added dropwise. The reaction mixture is allowed to warm to 23° C. then stirred overnight. The mixture is then treated with saturated aqueous NH4Cl, extracted with EtOAc, dried over magnesium sulfate, filtered, then concentrated in vacuo to give the title intermediate (54.7 g, 95%).

Workup

  1. temperatureto warm to 23° C.
  2. stirringthen stirred overnight
  3. extractionextracted with EtOAc
  4. dry with materialdried over magnesium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-501610bd1b1144b1aebbd51050d33f8f
Source dataset
uspto-grants-2013_12
Patent number
US08618300B2

Reaction notes

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