Diethyl Ether → 5-Methyl-2-hepten-4-ol

HRID 1284443

Reaction equation

HRID 1284443 reaction equation
[Mg:1].[Br:2][CH:3]([CH2:5][CH3:6])[CH3:4].[CH:7](=O)/[CH:8]=[CH:9]/[CH3:10].CC[O:14][CH2:15][CH3:16]>>[CH3:7][CH:8]([Mg:1][Br:2])[CH2:9][CH3:10].[CH3:4][CH:3]([CH2:5][CH3:6])[CH:15]([OH:14])[CH:16]=[CH:7][CH3:8]

Participants

6

Reactant 4

HCID 3283Diethyl Ether2×HCID 65542-BromobutaneHCID 447466CrotonaldehydeHCID 5462224Magnesium

Product 2

HCID 541810195-Methyl-2-hepten-4-olHCID 178456030HCID 178456030, compound

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

  1. additionare added dropwise to the solution at 0° to 10° C
  2. temperatureunder reflux temperature
  3. temperatureThereafter it is cooled
  4. extractionthe product extracted
  5. distillationdistilled

Sources & evidence

ORD record
ord-33d833bb18e341b188b1a474592984e9
Source dataset
uspto-grants-1986_01
Patent number
US04563365

Linked notes

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