Reaction equation
[CH3:1][CH:2]([CH2:8][CH3:9])[CH:3]([OH:7])[CH:4]=[CH:5][CH3:6].[Cr](O[Cr]([O-])(=O)=O)([O-])(=O)=O.[Na+].[Na+].S(=O)(=O)(O)O>>[CH3:1][CH:2]([CH2:8][CH3:9])[C:3](=[O:7])[CH:4]=[CH:5][CH3:6]Participants
Procedure
2-Butylmagnesium bromide is prepared from 24.32 g of magnesium filings and 137 g of 2-bromobutane in 100 ml of ether. 56 g of crotonaldehyde dissolved in 60 ml of ether are added dropwise to the solution at 0° to 10° C. The mixture is then boiled for 2 hours under reflux temperature. Thereafter it is cooled, the batch decomposed with ice water/hydrochloric acid and the product extracted, neutralized and distilled. 56 g of 5-methyl-hept-2-en-4-ol of boiling point 70° C./18 mb are obtained. To 52 g of this alcohol there is slowly added a mixture of 40.34 g of sodium dichromate and 54.1 g of sulphuric acid, while cooling with ice. After a further hour's reaction at room temperature, the batch is extracted with ether, the organic phase is washed until neutral, the solvent stripped off and the crude product distilled. Redistillation using a slotted tube column gives 17.2 g of 5-methyl-hept-2-en-4-one of boiling point 72° C./20 mb.
Workup
- temperaturewhile cooling with ice
- customAfter a further hour's reaction at room temperature
- extractionthe batch is extracted with ether
- washthe organic phase is washed until neutral, the solvent
- distillationthe crude product distilled
- distillationRedistillation
Sources & evidence
- ORD record
- ord-b736b6dc20184394b7860d2648656a47
- Source dataset
- uspto-grants-1987_03
- Patent number
- US04654168
Linked notes
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