3,7-Dimethylocta-2,6-Dienal → 6,10-Dimethyl-4-hydroxy-2,5,9-undecatriene

HRID 903295

Reaction equation

HRID 903295 reaction equation
[Mg].Br[CH:3]=[CH:4][CH3:5].[CH3:6][C:7](=[CH:9][CH2:10][CH2:11][C:12](=[CH:14][CH:15]=[O:16])[CH3:13])[CH3:8].[NH4+].[Cl-]>O1CCCC1>[CH3:13][C:12]([CH2:11][CH2:10][CH:9]=[C:7]([CH3:6])[CH3:8])=[CH:14][CH:15]([OH:16])[CH:3]=[CH:4][CH3:5]

Participants

6

Reactant 4

HCID 88433,7-Dimethylocta-2,6-DienalHCID 115331-Bromo-1-propene2×HCID 25517Ammonium ChlorideHCID 5462224Magnesium

Product 1

HCID 545494456,10-Dimethyl-4-hydroxy-2,5,9-undecatriene

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

12 g. of magnesium turnings were suspended under nitrogen in 250 ml. of dry tetrahydrofuran. Between 60° and 65°, 60 g. of 1-bromopropene dissolved in 50 ml. of tetrahydrofuran were added dropwise. During the addition, to prevent escaping of 1-bromopropene, the reflux condenser fitted on the reaction flask was cooled to -40°/-50°. When all Mg had reacted, the mixture was cooled to 20° and 76 g. of citral was added dropwise with cooling. After standing overnight, the mixture was poured into 1.5 liter of concentrated aqueous NH4Cl at 0°. The mixture was extracted 3 times with ether and the combined ether extracts treated as usual. After distillation, 6,10-dimethyl-4-hydroxy-2,5,9-undecatriene, b.p. 70°/0.1 Torr was obtained as a liquid with following constants : nD20 =1.4950; d420 =0.9145.

Workup

  1. customBetween 60°
  2. custom65°, 60 g
  3. additionDuring the addition
  4. customthe reflux condenser fitted on the reaction flask
  5. temperaturewas cooled to -40°/-50°
  6. customWhen all Mg had reacted
  7. temperaturethe mixture was cooled to 20°
  8. temperaturewith cooling
  9. extractionThe mixture was extracted 3 times with ether
  10. additionthe combined ether extracts treated as usual
  11. distillationAfter distillation, 6,10-dimethyl-4-hydroxy-2,5,9-undecatriene
  12. customb.p. 70°/0.1 Torr was obtained as a liquid with following constants

Sources & evidence

ORD record
ord-2a4e42d3df2640b28a5116a05b27342c
Source dataset
uspto-grants-1980_10
Patent number
US04226892

Linked notes

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