Water → gamma-Linolenyl alcohol

HRID 1451132Notes

Reaction equation

HRID 1451132 reaction equation
[H-].[Al+3].[Li+].[H-].[H-].[H-].[C:7](O)(=[O:25])[CH2:8][CH2:9][CH2:10][CH2:11]/[CH:12]=[CH:13]\[CH2:14]/[CH:15]=[CH:16]\[CH2:17]/[CH:18]=[CH:19]\[CH2:20][CH2:21][CH2:22][CH2:23][CH3:24].O.S(=O)(=O)(O)O>C(OCC)C>[CH2:7]([OH:25])[CH2:8][CH2:9][CH2:10][CH2:11]/[CH:12]=[CH:13]\[CH2:14]/[CH:15]=[CH:16]\[CH2:17]/[CH:18]=[CH:19]\[CH2:20][CH2:21][CH2:22][CH2:23][CH3:24]

Participants

6

Reactant 4

HCID 962WaterHCID 1118Sulfuric AcidHCID 5280933Gamma-Linolenic acidHCID 21226445Aluminium lithium hydride

Product 1

HCID 9795274gamma-Linolenyl alcoholYield 94.2%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

To a suspension of lithium aluminium hydride (50 g) in diethyl ether (1400 ml) under nitrogen was added dropwise with stirring a solution of z,z,z-octadeca-6,9,12-trienoic acid (97%, 200 g) at such a rate that a steady reflux occurred. The mixture was heated under reflux for 4 hours. After cooling to 0°-5° C., water (200 ml) was added cautiously to break down the complex, still maintaining a blanket of nitrogen. To the resulting slurry was added a 10% aqueous solution of sulphuric acid (1500 ml) and a two phase solution occurred. The aqueous layer was separated and the organic layer was washed with water (1000 ml), saturated aqueous sodium bicarbonate (2×1000 ml) and water (2×500 ml). The ether layer was dried (Na2SO4) and evaporated in vacuo to give a yellow oil. Distillation (148°-150° C./0.06 mmHg) gave z,z,z,-octadeca-6,9,12-trienol (179 g, 94% ) as a colourless oil.

Workup

  1. additionwas added dropwise
  2. temperaturea steady reflux
  3. temperatureThe mixture was heated
  4. temperatureunder reflux for 4 hours
  5. temperatureAfter cooling to 0°-5° C.
  6. temperaturestill maintaining a blanket of nitrogen
  7. customThe aqueous layer was separated
  8. washthe organic layer was washed with water (1000 ml), saturated aqueous sodium bicarbonate (2×1000 ml) and water (2×500 ml)
  9. dry with materialThe ether layer was dried (Na2SO4)
  10. customevaporated in vacuo
  11. customto give a yellow oil
  12. distillationDistillation (148°-150° C./0.06 mmHg)

Sources & evidence

ORD record
ord-765bc28825884249978e34762218419b
Source dataset
uspto-grants-1997_02
Patent number
US05603959

Reaction notes

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