反応 #794100

反応方程式

(carbethoxymethylene)triphenylphosphorane

Ethyl 2-fluoroacetate

diisobutylaluminum hydride

→

ethyl 4-fluorobut-2-enoate

溶媒

CH2Cl2

CH2Cl2

反応条件

後処理

1. 1
   温度maintaining the internal temperature below −70° C
2. 2
   その他was allowed to slowly reach room temperature
3. 3
   workup.STIRRINGwhile stirring overnight
4. 4
   その他It was then quenched with methanol
5. 5
   ろ過filtered
6. 6
   濃縮concentrated
7. 7
   その他to give the product
8. 8
   workup.ADDITIONas a mixture of isomers (E/Z=3:1)

実験手順

Ethyl 2-fluoroacetate (21.0 g) in CH2Cl2 (200 mL) at −78° C. was treated dropwise over 45 min with a 1.0 M solution of diisobutylaluminum hydride in CH2Cl2 (200 mL) maintaining the internal temperature below −70° C. Stirring was continued at −78° C. for 30 minutes and then (carbethoxymethylene)triphenylphosphorane (70.0 g) was added in one portion. The reaction mixture was allowed to slowly reach room temperature while stirring overnight. It was then quenched with methanol, filtered and concentrated to give the product as a mixture of isomers (E/Z=3:1).

出典