反応 #71006

反応方程式

but-3-en-2-one

but-3-en-2-one

2,4-dimethyl-1,3-pentadiene

Dichloromethane

THF

→

1-(2,2,4-trimethyl-cyclohex-3-enyl)-ethanone

溶媒

water

反応条件

後処理

1. 1
   温度In a 500 ml sulfonation flask with cooling funnel
2. 2
   温度White fumes and increase of temperature to 20° C.
3. 3
   その他was decreased to 15° C.
4. 4
   その他Exothermic reaction
5. 5
   workup.STIRRINGThe reaction mixture was stirred for 8 hours at 25° C. and for 10 hours at 45° C
6. 6
   workup.ADDITIONwas added dropwise (22 ml; 0.26 mol) (10 min)
7. 7
   workup.STIRRINGthe mixture was stirred for additional 48 hours at 25° C
8. 8
   workup.STIRRINGwas stirred for 5 min
9. 9
   ろ過filtered over celite
10. 10
    その他The red solution obtained
11. 11
    抽出extracted with dichloromethane (4×300 ml)
12. 12
    洗浄Combined organic layers were washed with brine (500 ml) and water (500 ml)
13. 13
    乾燥dried over sodium sulfate
14. 14
    ろ過filtered over silica
15. 15
    その他The solvent was removed in vacuo

実験手順

In a 500 ml sulfonation flask with cooling funnel, dropping funnel and mechanical stirring under air (*) at 5° C. was added but-3-en-2-one (43 ml; 0.52 mol) then THF (4.2 ml; 52 mmol) followed by a careful portionwise addition of aluminum chloride (3.5 g; 26 mmol). White fumes and increase of temperature to 20° C. were observed. The mixture turned red. The temperature was decreased to 15° C. and 2,4-dimethyl-1,3-pentadiene (68 ml; 0.52 mol) was added dropwise (90 min). Exothermic reaction was observed. The reaction mixture was stirred for 8 hours at 25° C. and for 10 hours at 45° C. As the diene was still detected but-3-en-2-one was added dropwise (22 ml; 0.26 mol) (10 min) and the mixture was stirred for additional 48 hours at 25° C. Dichloromethane (200 ml) was added to the mixture which was stirred for 5 min and filtered over celite. The red solution obtained was poured into cold water (1 l) and extracted with dichloromethane (4×300 ml). Combined organic layers were washed with brine (500 ml) and water (500 ml), dried over sodium sulfate and filtered over silica. The solvent was removed in vacuo to afford 84 g (97% of theory) of 1-(2,2,4-trimethyl-cyclohex-3-enyl)-ethanone as a clear red oil.

出典