5-Bromo-2-methyl-2-pentene → HCID 19043760, compound

HRID 1900137Notes

Reaction equation

HRID 1900137 reaction equation
CON(C)[C:4](=[O:16])[C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][C:6]=1O[Si](C)(C)C.[Mg].Br[CH2:20][CH2:21][CH:22]=[C:23]([CH3:25])[CH3:24].[OH:26]S([O-])(=O)=O.[K+]>>[OH:26][C:8]1[CH:7]=[CH:6][C:5]([C:4](=[O:16])[CH2:20][CH2:21][CH:22]=[C:23]([CH3:25])[CH3:24])=[CH:10][CH:9]=1

Participants

5

Reactant 4

HCID 1375215-Bromo-2-methyl-2-penteneHCID 516920Potassium bisulfateHCID 5462224MagnesiumHCID 19043695HCID 19043695, compound

Product 1

HCID 19043760HCID 19043760, compound

Procedure

A solution of 6.3 g of N-methoxy-N-methyl-trimethylsilanyloxybenzamide is added dropwise at 0° C. to a Grignard reagent prepared from 1 g of magnesium and 5.7 g of 1-bromo-4-methyl-3-pentene. The 15 reaction mixture is left to stand at room temperature overnight while stirring. The mixture is treated with 10% aqueous KHSO4 solution and then extracted with ethyl acetate. The organic phase is washed neutral with 10% aqueous NaCl solution, then dried and concentrated. The silyl group is cleaved in 10% aqueous THF with 1N hydrochloric acid. Then, the product is taken up in methylene chloride, dried and evaporated. After chromatography over silica gel while eluting with methylene chloride/5% methanol, there are obtained 2.1 g of 1-(4-hydroxy- phenyl)-5-methyl-hex-4-en-1-one. MS: m/e 204 (M+).

Workup

  1. customThe 15 reaction mixture
  2. waitis left
  3. extractionextracted with ethyl acetate
  4. washThe organic phase is washed neutral with 10% aqueous NaCl solution
  5. customdried
  6. concentrationconcentrated
  7. customdried
  8. customevaporated
  9. washAfter chromatography over silica gel while eluting with methylene chloride/5% methanol, there

Sources & evidence

ORD record
ord-33833f9c4db8474e8022237610fcaf6f
Source dataset
uspto-grants-1996_11
Patent number
US05574071

Reaction notes

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