Ethylene Glycol → 5-Octen-2-one, 6-methyl-

HRID 2164180Notes

Reaction equation

HRID 2164180 reaction equation
Br[CH2:2][CH2:3][CH2:4][C:5](=[O:7])[CH3:6].C(O)CO.[C:12]1(C)[CH:17]=CC(S(O)(=O)=O)=[CH:14][CH:13]=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>C1C=CC=CC=1.O.C(C(C)=O)C>[CH3:17][C:12]([CH2:13][CH3:14])=[CH:2][CH2:3][CH2:4][C:5](=[O:7])[CH3:6]

Participants

8

Reactant 4

HCID 174Ethylene GlycolHCID 6101p-Toluenesulfonic acidHCID 11776TriphenylphosphineHCID 774932-Pentanone, 5-bromo-

Product 1

HCID 911355-Octen-2-one, 6-methyl-

Reagents, catalysts & solvents 3

HCID 241BenzeneSolvent2×HCID 962WaterSolventHCID 6569Methyl Ethyl KetoneSolvent

Procedure

To a solution of 20.9 g. of the ethylene ketal of 1-bromo-4-pentanone (obtained by treating 1-bromo-4-pentanone with ethylene glycol in benzene in the presence of p-toluenesulfonic acid) in 100 ml. of benzene is added 20 g. of triphenylphosphine. The mixture is heated at reflux temperature for two hours and then filtered. The solid material thus-collected is washed with benzene, dried in vacuo and added to 6.49 g. of butyl lithium in 50 ml. of dimethylsulfoxide. The mixture is stirred until an orange solution is obtained and 38 g. of methyl ethyl ketone is then added. The mixture is stirred at about 25° for about eight hours, poured into water and then extracted with ether. The ethereal phase is concentrated and the concentrate added to 0.1N solution of hydrochloric acid in aqueous acetone and stirred for about 15 hours. The mixture is then poured into ice water and extracted with ethyl acetate. The extracts are combined, washed with water, dried over sodium sulfate and evaporated to yield 6-methyl-5-octen-2-one which is purified by chromatography and separated into the cis and trans isomer.

Workup

  1. temperatureThe mixture is heated
  2. temperatureat reflux temperature for two hours
  3. filtrationfiltered
  4. customThe solid material thus-collected
  5. washis washed with benzene
  6. customdried in vacuo
  7. additionadded to 6.49 g
  8. customis obtained
  9. stirringThe mixture is stirred at about 25° for about eight hours
  10. extractionextracted with ether
  11. concentrationThe ethereal phase is concentrated
  12. additionthe concentrate added to 0.1N solution of hydrochloric acid in aqueous acetone
  13. stirringstirred for about 15 hours
  14. additionThe mixture is then poured into ice water
  15. extractionextracted with ethyl acetate
  16. washwashed with water
  17. dry with materialdried over sodium sulfate
  18. customevaporated

Sources & evidence

ORD record
ord-faaf3b8e02804171ad955f237ed9c8e1
Source dataset
uspto-grants-1979_01
Patent number
US04137273

Reaction notes

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