Ethyl chloroformate → Ethyl 4-methylpent-2-ynoate

Participants

Reaction Steps

To a solution of 3-methylbut-1-yne (6.32 g), cooled in a dry-ice/acetone bath, in tetrahydrofuran (200 mL) is added 1.6 M N-butyl lithium solution (63.8 mL). After 1 h, ethyl chloroformate (9.33 mL) is added and the reaction mixture is stirred for an additional 1.5 h. The reaction mixture is allowed to warm to room temperature and is quenched with saturated ammonium chloride solution. The reaction is extracted two times with ethyl acetate. The organic layers are combined, washed with brine, dried over sodium sulfate, filtered, and concentrated under reduced pressure to give the title compound (11.5 g). 1H NMR (400 MHz, CDCl3) δ 3.75 (s, 3H), 2.8-2.65 (m, 1H), 1.25-1.23 (d, 6H).

Provenance & Evidence