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 (131.0 mL, 0.33 mol) was added dropwise over 30 minutes, 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) was added dropwise in THF (30 mL) and the mixture was stirred at −78° C. for 1 hour. Propargyl bromide (36.4 mL, 0.33 mol) was added dropwise in HMPA (60 mL). The mixture was stirred at −78° C. for 1 hour and then quenched with saturated NH4Cl solution and warmed to room temperature. THF was removed in vacuo, and the residue was dissolved in ether and washed four times with water. The organic layer was dried over MgSO4, filtered, and concentrated. The crude material was distilled under reduced pressure (˜29 in Hg, bp 68-70° C.) to obtain the desired product.

Provenance & Evidence