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

Participants

Reaction Conditions

Reaction Steps

Diisopropylamine (45.9 mL, 0.33 mol) was dissolved in THF (300 mL) and cooled to 0° C. under N2. n-Butyllithium (2.5M in hexanes; 131.0 mL, 0.33 mol) was added dropwise over 30 minutes, and the mixture was stirred at 0° C. for an additional 30 minutes and then cooled to −78° C. Ethyl isobutyrate (40 mL, 0.30 mol) in THF (30 mL) was added dropwise, and the solution was stirred at −78° C. for 1 hour. Propargyl bromide (36.4 mL, 0.33 moml) in HMPA (60 mL) was added dropwise, and the reaction was stirred at −78° C. for 1 hour and then quenched with saturated aqueous NH4Cl and warmed to room temperature. THF was removed in vacuo, and the residue was dissolved in Et2O and washed four times with H2O. The organic layer was dried over MgSO4, filtered, and concentrated, and the crude material was distilled under reduced pressure (˜29 inHg, by 68-70° C.) to give the title compound.

Provenance & Evidence