Réaction #1552081

Équation de réaction

HCl

Pyridinium dichromate

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

PDC

→

3d

Rendement 77.0%

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

Rendement 77.0%

Solvants

dimethylformamide

Conditions de réaction

Traitement

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

Mode opératoire

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.

Source