반응 #43559

반응 방정식

Water

n-BuLi

Methyl diethylphosphonoacetate

Trimethylacetaldehyde

→

4,4-Dimethyl-pent-2-enoic acid methyl ester

용매

THF

반응 조건

후처리

1. 1
   온도warmed to room temperature
2. 2
   workup.STIRRINGstirred overnight
3. 3
   기타to quench
4. 4
   추출extracted with ethyl ether (3×100 mL)
5. 5
   세척The combined organics were washed with brine
6. 6
   건조dried over MgSO4
7. 7
   여과filtered
8. 8
   기타evaporated

실험 절차

Methyl diethylphosphonoacetate (13.35 mL, 73.6 mmol, 1.05 eq.) was dissolved in THF (30 mL) and cooled to −78° C. in an acetone-dry ice bath. n-BuLi (1.6M in hexanes) (45.8 mL, 73.2 mmol, 1.05 eq.) was added slowly over 20 min. Trimethylacetaldehyde (6.0 g, 69.6 mmol, 1.0 eq.), was added to the reaction and allowed to stir at −78° C. for 20 minutes and warmed to room temperature and stirred overnight. Water (30 mL) was added to quench and extracted with ethyl ether (3×100 mL). The combined organics were washed with brine and dried over MgSO4, filtered and evaporated to provide 4,4-Dimethyl-pent-2-enoic acid methyl ester, a colorless liquid (8.52 g, 60.0 mmol, 86%) and was used directly in the next reaction. 1H NMR (CDCl3, 400 MHz) δ 0.89 (s, 9H), 3.64 (s, 3H), 5.64 (d, 1H, J=16.0 Hz), 6.88 (d, 1H, J=16.0 Hz).

출처