反应 #2348113

反应方程式

diethylzinc

sulfuric acid

3-ethyl-1-cyclohexene-1-yl propionate

propionic anhydride

2-cyclohexenone

→

3-ethylcyclohexanone

收率 75.0%

溶剂

toluene

toluene

反应条件

后处理

1. 1
   其他Placed in a 50-mL four-necked flask
2. 2
   其他equipped with a stirrer
3. 3
   workup.STIRRINGby further stirring for 10 min
4. 4
   温度The mixture was then cooled to −17° C.
5. 5
   workup.ADDITIONwas added dropwise to the mixture over the period of 1 hour
6. 6
   workup.ADDITIONAfter completion of the dropwise addition
7. 7
   workup.STIRRINGstirring
8. 8
   workup.WAITwas continued at the same temperature for 6 hours
9. 9
   workup.ADDITIONwas added to the reaction solution
10. 10
    其他for quenching
11. 11
    其他After separation
12. 12
    洗涤the organic layer was washed (5 times)
13. 13
    浓缩the resultant organic layer was concentrated under reduced pressure
14. 14
    其他to give 1.58 g of a crude product
15. 15
    其他The crude product was purified by silica-gel column chromatography
16. 16
    其他to produce 1.37 g (7.5 mmol), 75% yield

实验过程

Placed in a 50-mL four-necked flask equipped with a stirrer, thermometer and dropping funnel were 36.2 mg (0.1 mmol) of Cu(OTf)2, 10 g of toluene and 87.1 mg (0.2 mmol) of the ligand, and the inner atmosphere was replaced with nitrogen. After replacement with nitrogen, the mixture was stirred at 25° C. for 20 min. Then, 16 mL (17.6 mmol) of a toluene solution (1.1 mol/L) of diethylzinc was added to the mixture at 25° C., followed by further stirring for 10 min. The mixture was then cooled to −17° C., followed by addition of 1.43 g (11 mmol) of propionic anhydride, and 0.96 g (10 mmol) of 2-cyclohexenone was added dropwise to the mixture over the period of 1 hour. After completion of the dropwise addition, stirring was continued at the same temperature for 6 hours. After the reaction was completed, 34.5 g of a 5% aqueous sulfuric acid solution as cooled to 0° C. was added to the reaction solution for quenching. After separation, the organic layer was washed (5 times), and the resultant organic layer was concentrated under reduced pressure to give 1.58 g of a crude product. The crude product was purified by silica-gel column chromatography to produce 1.37 g (7.5 mmol), 75% yield, of 3-ethyl-1-cyclohexene-1-yl propionate. A portion of the compound was hydrolyzed by the conventional method to give 3-ethylcyclohexanone, which was then subjected to determination of optical purity and identified as the (R) isomer with 34.0% ee of optical purity.

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