2-Cyclohexen-1-one → 3-Butylcyclohexanone
Reaktionsgleichung
[CH2:1]([Mg]Cl)[CH2:2][CH2:3][CH3:4].[C:7]1(=[O:13])[CH2:12][CH2:11][CH2:10][CH:9]=[CH:8]1>C1COCC1>[CH2:1]([CH:9]1[CH2:10][CH2:11][CH2:12][C:7](=[O:13])[CH2:8]1)[CH2:2][CH2:3][CH3:4]Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Reaktionsbedingungen
- Temperatur
- -78 °C
Versuchsvorschrift
A THF (5 mL) suspension of CuBr.Me2S (26.3 mg, 0.128 mmol) was treated with 1.0 equiv of n-BuLi at -78° C. under an argon atmosphere. The mixture was allowed to warm up slightly with the formation of a bright yellow solid. The mixture was again cooled to -78° C. and treated with Li(CHIRAMT) formed from compound 4 (85.8 mg, 0.261 mmol) and n-BuLi (1.0 equiv). The yellow slurry was stirred with gradual warming until a homogeneous burgundy solution was obtained. In the case of R=Me, a homogeneous mixture was not obtained even after prolonged stirring at room temperature, and it was evident that unreacted (CuMe)n was still present. The solution was cooled to -78° C. and THF (8 mL each) solutions of n-BuMgCl (25.0 equiv) and cyclohexenone (0.3068 g, 3.19 mmol) were added dropwise and simultaneously over a 5 min period. The resulting reaction mixture was stirred for an additional 10 min at -78° C., quenched with saturated aqueous NH4Cl solution (7 mL), and worked up as described in the previous section. Pure 3-butylcyclohexanone (0.4617 g, 94%) was obtained as checked by glc.