(3,4,5-Trimethyl-2-thenyl)-triphenyl phosphonium bromide → trans-3,7-Dimethyl-9-(3,4,5-trimethyl-2-thienyl)-2,4,6,8-nonatetraenoic acid ethyl ester

HRID 1764554Notes

Reaction equation

HRID 1764554 reaction equation
[Br-].[CH3:2][C:3]1[C:7]([CH3:8])=[C:6]([CH3:9])[S:5][C:4]=1[CH2:10][P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.[CH2:30]([O:32][C:33](=[O:44])[CH:34]=[C:35]([CH3:43])[CH:36]=[CH:37][CH:38]=[C:39]([CH:41]=O)[CH3:40])[CH3:31]>C1OCCC1.CO.O>[CH2:30]([O:32][C:33](=[O:44])[CH:34]=[C:35]([CH3:43])/[CH:36]=[CH:37]/[CH:38]=[C:39]([CH3:41])[CH:40]=[CH:10][C:4]1[S:5][C:6]([CH3:9])=[C:7]([CH3:8])[C:3]=1[CH3:2])[CH3:31]

Participants

5

Reactant 2

HCID 20285709(3,4,5-Trimethyl-2-thenyl)-triphenyl phosphonium bromideHCID 54295620Ethyl 3,7-dimethyl-8-oxoocta-2,4,6-trienoate

Product 1

HCID 131710955trans-3,7-Dimethyl-9-(3,4,5-trimethyl-2-thienyl)-2,4,6,8-nonatetraenoic acid ethyl ester

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 22242641Methanol--water (1/1)Solvent

Procedure

3.2 G. of (3,4,5-trimethyl-2-thenyl)triphenyl phosphonium bromide were suspended in 80 ml of butylene oxide and 1.5 g. of 3-methyl-7-formyl-octa-2,4,6-trienoic acid ethyl ester were added. The resulting mixture was refluxed under argon for one hour after which the solvent was evaporated. The residue which formed was diluted with a mixture of methanol/water (6:4) and extracted four times with hexane. The combined hexane solutions were washed once with methanol/water (6:4) and twice with pure water, dried with sodium sulfate, filtered and evaporated. The resulting crude product was purified by column chromatography on silica gel and elution with hexane/5% ether. Recrystallization of the all trans-3,7-dimethyl-9-(3,4,5-trimethyl-2-thienyl)-2,4,6,8-nonatetraenoic acid ethyl ester so obtained from hexane/1% ethyl acetate gave yellow crystals, m.p. 96°-98° C.

Workup

  1. temperatureThe resulting mixture was refluxed under argon for one hour after which the solvent
  2. customwas evaporated
  3. customThe residue which formed
  4. extractionextracted four times with hexane
  5. washThe combined hexane solutions were washed once with methanol/water (6:4) and twice with pure water
  6. dry with materialdried with sodium sulfate
  7. filtrationfiltered
  8. customevaporated
  9. customThe resulting crude product was purified by column chromatography on silica gel and elution with hexane/5% ether
  10. customRecrystallization of the all trans-3,7-dimethyl-9-(3,4,5-trimethyl-2-thienyl)-2,4,6,8-nonatetraenoic acid ethyl ester
  11. customso obtained from hexane/1% ethyl acetate
  12. customgave yellow crystals, m.p. 96°-98° C.

Sources & evidence

ORD record
ord-1fa1cffa49034164910346cb7fe2cf01
Source dataset
uspto-grants-1978_09
Patent number
US04116975

Reaction notes

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