Reaktion #570316

Reaktionsgleichung

6-carbomethoxymethyl-6-ethyl-2-cyclohexene-1-one

6-Carbomethoxymethyl-6-ethyl-2-cyclohexen-1-one

isopropenylmagnesium bromide

Me2S

Me2S

→

colorless oil

Ausbeute 71.0%

2-Carbomethoxymethyl-2-ethyl-5-(1-methylethenyl)-cyclohexanone

Ausbeute 71.0%

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONadded dropwise
2. 2
   SonstigeThe reaction was quenched with 120 ml of 1M HCl (aq.)
3. 3
   Extraktionextracted with 4×60 ml of petroleum ether
4. 4
   TrocknenDrying (Na2SO4) and flash chromatography

Vorschrift

The enone, 6-carbomethoxymethyl-6-ethyl-2-cyclohexene-1-one, (X), prepared in Example 1, Step (c), (33.12 mmol, 6.50 g), CuBr.Me2S (3.312 mmol, 681 mg) and Me2S (6.63 ml) were stirred in 97.5 ml of dry THF at -40° C. under nitrogen and treated with 49.68 mmol (66.24 ml of 0.75M in THF, prepared from treating isopropenyl bromide with 1.1 equivalents of Mg) of isopropenylmagnesium bromide added dropwise. The reaction was quenched with 120 ml of 1M HCl (aq.) and extracted with 4×60 ml of petroleum ether. Drying (Na2SO4) and flash chromatography afforded 5.6 g (23.53 mmol, 71%) of colorless oil as a mixture of diastereomers. The diastereomers were separted by preparative HPLC on a Prep 500A using a brand of silica gel available from Waters Associaes, Milford, Ma., to provide a "less polar isomer" and a "more polar isomer."

Quelle