Reaktion #336308

Reaktionsgleichung

NaH

ethyl propionylacetate

(E)-geranyl bromide

→

pure product

Ausbeute 77.3%

(E)-5,9-Dimethyl-2-(1-oxopropyl)-4,8-decadienoic acid, ethyl ester

Ausbeute 77.3%

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Waschenin mineral oil (washed three times with pentane) in 200 mL of tetrahydrofuran at 0° C. under argon
2. 2
   Sonstigequenched with NH4Cl
3. 3
   workup.ADDITIONdiluted with 500 mL of diethyl ether
4. 4
   WaschenThe organic layer was washed with water and brine
5. 5
   Trocknendried over MgSO4
6. 6
   Sonstigeto obtain 20.157 g of crude product as a yellow oil
7. 7
   SonstigePurification by flash chromatography on 800 g of silica gel
8. 8
   Wascheneluted with 3:97 ethyl acetate

Vorschrift

To a suspension of 3.92 g (97.5 mmol, 3 equiv) of 60% NaH in mineral oil (washed three times with pentane) in 200 mL of tetrahydrofuran at 0° C. under argon was added dropwise a solution of 15.3 mL (107 mmol, 3.3 equiv) of ethyl propionylacetate. After 0.5 hour, a solution of 7.04 g (32.4 mmol) of (E)-geranyl bromide in 20 mL of tetrahydrofuran was added dropwise over 45 minutes. The mixture was stirred one hour at 0° C. and one hour at room temperture, quenched with NH4Cl and diluted with 500 mL of diethyl ether. The organic layer was washed with water and brine, and dried over MgSO4 to obtain 20.157 g of crude product as a yellow oil. Purification by flash chromatography on 800 g of silica gel, eluted with 3:97 ethyl acetate:hexanes provided 7.024 g (77%) of pure product as a clear, colorless oil.

Quelle