反应 #346337

反应方程式

ammonium chloride

lithium dimethyl-copper

11β-trimethylsiloxy-21-acetoxy-6α-fluoropregna-1,4,16-triene-3,20-dione

→

11β-trimethylsiloxy-21-acetoxy-6α-fluoro-16α-methyl-pregna-1,4-diene-3,20-dione

溶剂

dichloromethane

dichloromethane

反应条件

后处理

1. 1
   温度cooling
2. 2
   workup.ADDITIONby drop wise addition
3. 3
   温度maintaining the temperature below -5°
4. 4
   其他obtained
5. 5
   其他was kept below -1°
6. 6
   温度the stirring was maintained for a period of 15 minutes
7. 7
   其他the organic phase separated
8. 8
   萃取the aqueous phase re-extracted with dichloromethane
9. 9
   洗涤washed with water
10. 10
    干燥dried over anhydrous sodium sulfate
11. 11
    浓缩concentrated to dryness under reduced pressure

实验过程

750 mg cuprous iodide was suspended in 10 ml dichloromethane in an atmosphere of nitrogen and cooled to -10° C. To this suspension under stirring and cooling was added 9 ml of a 2% solution of lithium-methyl by drop wise addition maintaining the temperature below -5°. To the so obtained lithium-dimethyl-copper solution was added 425 mg 11β-trimethylsiloxy-21-acetoxy-6α-fluoropregna-1,4,16-triene-3,20-dione obtained according to Example 8 dissolved in 3 ml dichloromethane. The temperature of the reaction mixture was kept below -1°, and the stirring was maintained for a period of 15 minutes. The reaction mixture was poured into an aqueous ammonium chloride solution, the organic phase separated and the aqueous phase re-extracted with dichloromethane. The organic extracts were combined, washed with water, dried over anhydrous sodium sulfate and concentrated to dryness under reduced pressure. Trituration with acetone afforded a crystalline product 11β-trimethylsiloxy-21-acetoxy-6α-fluoro-16α-methyl-pregna-1,4-diene-3,20-dione (compound 14) yield 320 mg TLC: homogeneous.

来源