Реакция #1552081

Уравнение реакции

HCl

Pyridinium dichromate

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

PDC

→

3d

Выход 77.0%

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

Выход 77.0%

Растворители

dimethylformamide

Условия реакции

Обработка

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

Методика

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.

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