反応 #42021

反応方程式

KMnO4

ethyl chrysanthemumate

potassium permanganate

acetone

KMnO4

KMnO4

→

caronic acid

反応条件

後処理

1. 1
   ろ過filtered
2. 2
   洗浄The solid cake was washed with acetone (450 mL) and suction
3. 3
   その他dried
4. 4
   workup.ADDITIONThe dried solid was mixed with sodium sulfite (Na2SO3) (364.3 g)
5. 5
   workup.ADDITIONthe solid mixture was added in portions to 30% sulfuric acid (H2SO4) (960 mL)
6. 6
   温度while maintaining the temperature below 65° C
7. 7
   workup.ADDITIONEthyl acetate (EtOAc) (1000 mL) was added
8. 8
   ろ過the mixture was filtered through celite
9. 9
   その他The layers were separated
10. 10
    洗浄the aqueous layer was washed with EtOAc (600 mL)
11. 11
    乾燥The combined organic solutions were dried over anhydrous sodium sulfate
12. 12
    濃縮concentrated to an oil (158.6 g)
13. 13
    workup.ADDITIONThis oil was treated with 45% sodium hydroxide solution (NaOH) (240 mL) and water (100 mL) at 85° C. for about 30 min
14. 14
    温度The reaction mixture was cooled
15. 15
    抽出further extracted three times with EtOAc (450 mL)
16. 16
    乾燥The combined organic layers were dried over anhydrous sodium sulfate
17. 17
    濃縮concentrated

実験手順

To a solution of ethyl chrysanthemumate (163.1 g) in acetone (600 mL) at 20° C. was added potassium permanganate (KMnO4) (472.7 g) as a solid in 9 equal portions. After each addition of KMnO4, the exotherm that ensued was allowed to subside before the addition of the next portion of KMnO4. Upon completion of KMnO4 addition, the reaction mixture was stirred for another 2 hours and then filtered. The solid cake was washed with acetone (450 mL) and suction dried. The dried solid was mixed with sodium sulfite (Na2SO3) (364.3 g), and the solid mixture was added in portions to 30% sulfuric acid (H2SO4) (960 mL) while maintaining the temperature below 65° C. Ethyl acetate (EtOAc) (1000 mL) was added, and the mixture was filtered through celite. The layers were separated and the aqueous layer was washed with EtOAc (600 mL). The combined organic solutions were dried over anhydrous sodium sulfate and concentrated to an oil (158.6 g). This oil was treated with 45% sodium hydroxide solution (NaOH) (240 mL) and water (100 mL) at 85° C. for about 30 min. The reaction mixture was cooled, acidified to pH 3 with 30% sulfuric acid (about 300 mL) and further extracted three times with EtOAc (450 mL). The combined organic layers were dried over anhydrous sodium sulfate and concentrated to give caronic acid (162.6 g) as a mixture of cis- and trans-isomers. 1H NMR (400 MHz, CD3OD); cis-isomer δ1.26 (s, 3H), 1.40 (s, 3H), 1.96 (s, 2H); trans-isomer δ1.32 (s, 6H), 2.19 (s, 2H).

出典