Reaktion #1907757

Reaktionsgleichung

HCl

acetaldehyde

5-bromo-cyclooctene

magnesium

→

1-cyclooct-4-enylethanone

Ausbeute 30.3%

Lösungsmittel

diethyl ether

diethyl ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionextracted with diethyl ether
2. 2
   WaschenThe organic phases were washed successively with NaHCO3, NH4Cl and NaCl solutions
3. 3
   Trocknendried (Na2SO4)
4. 4
   Sonstigethe solvent evaporated under vacuum
5. 5
   SonstigeThe crude product was purified by flash chromatography (hexane/Et2O 10:1)

Vorschrift

A solution of 5-bromo-cyclooctene (5 g, 26 mmol; prepared by treatment of 1,5-cyclooctadiene with HBr in AcOH) in diethyl ether was added to magnesium (0.7 g, 29 mmol, 1.1 eq.). The resulting solution was cooled to 5° C. and treated dropwise with a solution of acetaldehyde (5 ml, 89 mmol, 3.4 eq.) in diethyl ether (10 ml). The resulting mixture was stirred 3 h at 20° C., treated with 2M HCl, and extracted with diethyl ether. The organic phases were washed successively with NaHCO3, NH4Cl and NaCl solutions, and dried (Na2SO4) and the solvent evaporated under vacuum. The crude product was purified by flash chromatography (hexane/Et2O 10:1) to give 1.2 g of 1-cyclooct-4-enylethanone (30%).

Quelle