反应 #43559

反应方程式

Water

n-BuLi

Methyl diethylphosphonoacetate

Trimethylacetaldehyde

→

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

溶剂

THF

反应条件

后处理

1. 1
   温度warmed to room temperature
2. 2
   workup.STIRRINGstirred overnight
3. 3
   其他to quench
4. 4
   萃取extracted with ethyl ether (3×100 mL)
5. 5
   洗涤The combined organics were washed with brine
6. 6
   干燥dried over MgSO4
7. 7
   过滤filtered
8. 8
   其他evaporated

实验过程

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).

来源