Reaktion #669936

Reaktionsgleichung

sodium cyclopentadienylide

1-bromo-2-fluoroethane

sodium hydroxide

hydrogen peroxide

2-methyl-2-butene

→

(RS)-3-(2-fluoroethyl)-3-cyclopenten-1-ol

Ausbeute 16.0%

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturcooling and under nitrogen
2. 2
   SonstigeThe resulting reaction liquid
3. 3
   Filtrationwas filtered with cerite, and the filtrate
4. 4
   workup.ADDITIONwas added under ice-
5. 5
   Temperaturcooling and under nitrogen stream to a tetrahydrofuran solution of disiamylborane
6. 6
   Sonstigeprepared
7. 7
   workup.STIRRINGthe resulting mixture was stirred for 8 hours
8. 8
   Temperaturcooling to the reaction liquid
9. 9
   Sonstigeobtained above, and the resulting mixture
10. 10
    workup.STIRRINGwas stirred for 1 hour
11. 11
    SonstigeThe reaction liquid
12. 12
    Sonstigethus obtained
13. 13
    Extraktionwas extracted two times with diethyl ether
14. 14
    WaschenThe combined ether layer was washed with saturated aqueous sodium chloride solution
15. 15
    Trocknendried over anhydrous magnesium sulfate
16. 16
    workup.DISTILLATIONthe solvent was distilled off under reduced pressure
17. 17
    SonstigeThe residue obtained

Vorschrift

To 25 ml of 2 M tetrahydrofuran solution of sodium cyclopentadienylide was added under ice-cooling and under nitrogen stream 6.3 g of 1-bromo-2-fluoroethane and stirred for 2 hours. The resulting reaction liquid was filtered with cerite, and the filtrate was added under ice-cooling and under nitrogen stream to a tetrahydrofuran solution of disiamylborane prepared by using 75 ml of 1 M borane-tetrahydrofuran complex and 18.5 ml of 2-methyl-2-butene and the resulting mixture was stirred for 8 hours. Then 3 N aqueous sodium hydroxide solution and 30% aqueous hydrogen peroxide were successively added under ice-cooling to the reaction liquid obtained above, and the resulting mixture was stirred for 1 hour. The reaction liquid thus obtained was extracted two times with diethyl ether. The combined ether layer was washed with saturated aqueous sodium chloride solution, then dried over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue obtained was subjected to silica gel column chromatography to obtain 1.1 g of (RS)-3-(2-fluoroethyl)-3-cyclopenten-1-ol. Yield 16%

Quelle