N,N,N',N'-Tetramethylethylenediamine → HCID 67871871, compound

HRID 655045Notes

Reaction equation

HRID 655045 reaction equation
CN(C)[CH2:3][CH2:4]N(C)C.[CH2:9]([Li])[CH2:10]CC.C([C@@H:17]1[CH2:22][C:21](=[O:23])[C:20]([CH3:24])=[CH:19][CH2:18]1)(=O)C>[Br-].C([P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)C.O1CCCC1>[CH3:24][C:20]1[C:21](=[O:23])[CH2:22][C@@H:17](/[C:3](/[CH3:4])=[CH:9]\[CH3:10])[CH2:18][CH:19]=1

Participants

6

Reactant 3

HCID 8037N,N,N',N'-TetramethylethylenediamineHCID 42586447HCID 42586447, compoundHCID 178418339Butyllithium

Product 1

HCID 67871871HCID 67871871, compound

Reagents, catalysts & solvents 2

HCID 73727Phosphonium, ethyltriphenyl-, bromide (1:1)CatalystHCID 8028TetrahydrofuranSolvent2×

Procedure

4.5 g of ethyltriphenylphosphonium bromide and 1.8 ml of N,N,N',N'-tetramethyl-ethylenediamine are cooled to 0° in 300 ml of tetrahydrofuran under argon. 7.5 ml of n-butyllithium (1.6M in hexane) are then added dropwise thereto while stirring and the mixture is stirred for a further 1 hour without cooling with ice. The red solution is cooled to -70°, whereupon 1.52 g of (S)-5-acetyl-2-methyl- 2-cyclohexen-1-one dissolved in 10 ml of tetrahydrofuran are added dropwise thereto during 15 minutes. The cooling bath is removed and the mixture is stirred for a further 45 minutes. After adding 20 ml of water the mixture is evaporated. The residue is taken up in ether and extracted twice with 0.3N sulphuric acid and twice with saturated sodium chloride solution. The ether phase is dried over sodium sulphate and evaporated. The crude product is purified by flash chromatography on silica gel while eluting with hexane/methylene chloride (1:1). There is obtained (5S)-2-methyl-5-[(Z)-1-methylpropenyl]-2-cyclohexen-1-one as a colourless oil [mass spectrum: peaks inter alia at m/e 164 (M+), 149 (M+ -15,CH3), 135 (M+ -29,COH), 82 and 54].

Workup

  1. stirringthe mixture is stirred for a further 1 hour
  2. temperaturewithout cooling with ice
  3. additionare added dropwise
  4. customThe cooling bath is removed
  5. stirringthe mixture is stirred for a further 45 minutes
  6. additionAfter adding 20 ml of water the mixture
  7. customis evaporated
  8. extractionextracted twice with 0.3N sulphuric acid and twice with saturated sodium chloride solution
  9. dry with materialThe ether phase is dried over sodium sulphate
  10. customevaporated
  11. customThe crude product is purified by flash chromatography on silica gel
  12. washwhile eluting with hexane/methylene chloride (1:1)

Sources & evidence

ORD record
ord-84f80efd1d304f70a77135443277ac96
Source dataset
uspto-grants-1992_07
Patent number
US05134240

Reaction notes

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