Reaktion #87106

Reaktionsgleichung

NH4Cl

n-BuLi

isopropenyl bromide

tert-butyl ((2S)-1-(methoxy(methyl)amino)-1-oxo-3-(2-oxopyrrolidin-3-yl) propan-2-yl)carbamate

→

tert-butyl ((2S)-4-methyl-3-oxo-1-(2-oxopyrrolidin-3-yl)pent-4-en-2-yl)carbamate

Ausbeute 42.7%

Lösungsmittel

THF

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGThe reaction mixture was stirred at −78° C. for 3 h
2. 2
   Temperaturto warm to ambient temperature
3. 3
   workup.STIRRINGstirred for 12 h
4. 4
   Extraktionthe resulting mixture was extracted with EtOAc (50 mL×2)
5. 5
   WaschenThe combined extracts were washed with brine
6. 6
   Trocknendried over anhydrous sodium sulfate
7. 7
   Einengenconcentrated
8. 8
   SonstigeThe residue was purified by flash column chromatography on silica gel (petroleum ether/EtOAc=20:1)

Vorschrift

n-BuLi (2.5 M, 3.17 mL, 7.9 mmol) was added dropwise to a solution of isopropenyl bromide (0.9 g, 8.3 mmol) in THF (15.0 mL) at −78° C. and the mixture was stirred at −78° C. for 30 min. A solution of tert-butyl ((2S)-1-(methoxy(methyl)amino)-1-oxo-3-(2-oxopyrrolidin-3-yl) propan-2-yl)carbamate (500 mg, 1.58 mmol) in THF (5.0 mL) was added dropwise. The reaction mixture was stirred at −78° C. for 3 h and then allowed to warm to ambient temperature and stirred for 12 h. Saturated aqueous NH4Cl (50 mL) was added and the resulting mixture was extracted with EtOAc (50 mL×2). The combined extracts were washed with brine, dried over anhydrous sodium sulfate, and concentrated. The residue was purified by flash column chromatography on silica gel (petroleum ether/EtOAc=20:1) to afford tert-butyl ((2S)-4-methyl-3-oxo-1-(2-oxopyrrolidin-3-yl)pent-4-en-2-yl)carbamate (200 mg, 42% yield) as a yellow oil.

Quelle