Lithium (trimethylsilyl)acetylide → Tert-butyl N-[1-(prop-2-ynoyl)cyclopropyl]carbamate

Participants

Reaction Steps

To a solution of [1-(Methoxy-methyl-carbamoyl)-cyclopropyl]-carbamic acid tert-butyl ester (5.0 g, 20. mmol) in anhydrous THF (50 mL) at −78° C., was slowly added lithium (trimethylsilyl)acetylide (0.5 M in THF, 81 mL, 41 mmol). The reaction stirred at this temperature for 2 h then an additional amount of lithium (trimethylsilyl)acetylide (0.5 M in THF, 81 mL, 41 mmol) was added and stirring continued for 3 h at −78° C. The reaction was diluted with saturated aqueous NH4Cl and extracted with EtOAc. The organic layer was washed with brine, dried over Na2SO4, and concentrated in vacuo. The material was purified by flash chromatography (silica, 15% EtOAc/petroleum ether) to give 550 mg of the title compound as a brown syrup, m/z 154.18 [M-t-Bu]+.

Provenance & Evidence