反応 #1552081

反応方程式

HCl

Pyridinium dichromate

1-(4-Isobutyl-1,6-dimethylcyclohex-3-enyl)ethanol

PDC

→

3d

収率 77.0%

1-(4-Isobutyl-1,6-dimethylcyclohex-3-enyl)ethanone

収率 77.0%

溶媒

dimethylformamide

反応条件

後処理

1. 1
   温度cooled to below 5° C. under nitrogen
2. 2
   その他to return to room temperature
3. 3
   workup.ADDITIONwas added and after a further 90 min the reaction
4. 4
   workup.ADDITIONadded
5. 5
   抽出After brief agitation the product was extracted from the aqeuous phase with MTBE
6. 6
   洗浄washed with sat. NaHCO3 solution
7. 7
   乾燥After drying (Na2SO4) the solvent
8. 8
   その他was removed in vacuo
9. 9
   その他to give 1.8 g of a crude oil which
10. 10
    その他was purified by flash chromatography (MTBE/hexane 2:8)

実験手順

1-(4-Isobutyl-1,6-dimethylcyclohex-3-enyl)ethanol 4d (2 g, 9 mmol) was dissolved in dimethylformamide (50 ml) and cooled to below 5° C. under nitrogen. Pyridinium dichromate (4.5 g, 12 mmol) was added in two portions with stirring and the reaction allowed to return to room temperature. After stirring for 90 min another portion of PDC (1 g, 2.7 mmol) was added and after a further 90 min the reaction was complete. The reaction mixture was poured onto ice-water and 2M HCl added. After brief agitation the product was extracted from the aqeuous phase with MTBE. The organic phases were combined and washed with sat. NaHCO3 solution then to pH 7 with brine. After drying (Na2SO4) the solvent was removed in vacuo to give 1.8 g of a crude oil which was purified by flash chromatography (MTBE/hexane 2:8). Combination of pure fractions gave 3d as a 7:3 mixture of diastereomers (1.5 g, 77% yield, 99% pure). Subsequent distillation provided a sample for olfactory assessment.

出典