Tetrahydrofuran → HCID 67872175, compound

HRID 655044Notes

Reaction equation

HRID 655044 reaction equation
[CH2:1]([Li])[CH2:2][CH2:3]C.[C:6]([C@@H:9]1[CH2:14][C:13](=[O:15])[C:12]([CH3:16])=[CH:11][CH2:10]1)(=O)[CH3:7].O1CCC[CH2:18]1>[Br-].C([P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)CCC.CCCCCC>[CH3:16][C:12]1[C:13](=[O:15])[CH2:14][C@@H:9](/[C:6](/[CH3:18])=[CH:7]\[CH2:1][CH2:2][CH3:3])[CH2:10][CH:11]=1

Participants

6

Reactant 3

HCID 8028Tetrahydrofuran2×HCID 42586447HCID 42586447, compoundHCID 178418339Butyllithium

Product 1

HCID 67872175HCID 67872175, compound

Reagents, catalysts & solvents 2

HCID 159628Butyltriphenylphosphonium bromideCatalystHCID 8058HexaneSolvent

Procedure

44 g of n-butyltriphenylphosphonium bromide are suspended in 500 ml of dry tetrahydrofuran under argon and cooled to -50°. 69 ml of 1.33N n-butyllithium in hexane are added thereto. The orange coloured suspension is warmed to room temperature and then again cooled to -50°. 14 g of (5S)-5-acetyl-2-methyl-2-cyclohexen-1-one dissolved in 20 ml of dry tetrahydrofuran are added dropwise thereto over a period of 20 minutes. The cooling bath is then removed and the suspension is left to warm to room temperature. After stirring for 2 hours the reaction mixture is filtered through siliceous earth. The filtrate is evaporated, the dark residue is dissolved in 500 ml of ethyl acetate and washed twice with 200 ml of water each time. The organic phase is dried over sodium sulphate and evaporated. The thus-obtained oil is purified by column chromatography on silica gel with hexane/ethyl acetate (95:5) as the elution agent. There is obtained (5S)-2-methyl-5-[(Z)-1-methyl-1-pentenyl]-2-cyclohexen-1-one which still contains about 15% of the corresponding (E)-isomer.

Workup

  1. temperaturecooled to -50°
  2. temperatureagain cooled to -50°
  3. additionare added dropwise
  4. customThe cooling bath is then removed
  5. waitthe suspension is left
  6. temperatureto warm to room temperature
  7. filtrationis filtered through siliceous earth
  8. customThe filtrate is evaporated
  9. dissolutionthe dark residue is dissolved in 500 ml of ethyl acetate
  10. washwashed twice with 200 ml of water each time
  11. dry with materialThe organic phase is dried over sodium sulphate
  12. customevaporated
  13. customThe thus-obtained oil is purified by column chromatography on silica gel with hexane/ethyl acetate (95:5) as the elution agent

Sources & evidence

ORD record
ord-3ea02d74454f4a17a9bdc9a0f2dcd94c
Source dataset
uspto-grants-1992_07
Patent number
US05134240

Reaction notes

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