Sulfuric Acid → 5-Methyl-2-hepten-4-one (natural)

HRID 1284444ノート

反応式

HRID 1284444 の反応式
[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]

参加物

4

反応物 3

HCID 1118Sulfuric AcidHCID 25408Sodium DichromateHCID 541810195-Methyl-2-hepten-4-ol

生成物 1

HCID 5177915-Methyl-2-hepten-4-one (natural)収率 33.6%

実験手順

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.

後処理

  1. temperaturewhile cooling with ice
  2. customAfter a further hour's reaction at room temperature
  3. extractionthe batch is extracted with ether
  4. washthe organic phase is washed until neutral, the solvent
  5. distillationthe crude product distilled
  6. distillationRedistillation

出典と根拠

ORDレコード
ord-cf66dbb9a2544224bd9f514c241a8a78
出典データセット
uspto-grants-1986_01
特許番号
US04563365

反応ノート

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