Aluminium lithium hydride → rac. E-8-Benzyloxy-3,7-dimethyl-4-octen-1-ol

HRID 972055Notes

Reaction equation

HRID 972055 reaction equation
[H-].[Al+3].[Li+].[H-].[H-].[H-].[CH2:7]([O:14][CH2:15][CH:16]([CH3:28])[CH2:17][CH:18]=[CH:19][CH:20]([CH3:27])[CH2:21][C:22](OCC)=[O:23])[C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1>CCOCC>[CH2:7]([O:14][CH2:15][CH:16]([CH3:28])[CH2:17]/[CH:18]=[CH:19]/[CH:20]([CH3:27])[CH2:21][CH2:22][OH:23])[C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1

Participants

4

Reactant 2

HCID 21226445Aluminium lithium hydrideHCID 57270638Rac. ethyl 8-benzyloxy-3,7-dimethyl-4-octenoate

Product 1

HCID 12923303rac. E-8-Benzyloxy-3,7-dimethyl-4-octen-1-ol

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent2×

Procedure

A suspension of 0.432 g. (11.36 mmoles) of lithium aluminum hydride in 20 ml. of anhydrous ether was stirred with ice bath cooling while a solution of 1.73 g. (5.68 mmoles) of rac. ethyl 8-benzyloxy-3,7-dimethyl-4-octenoate in 20 ml. of anhydrous ether was added over a 25 minute period keeping the temperature at 0°-5° C. The cooling bath was removed and the reaction mixture was stirred at room temperature for 2.5 hours at the end of which time 1.6 ml. of saturated sodium sulfate solution was cautiously added with ice bath cooling. After stirring for 16 hours at room temperature, the slurry was filtered on Celite and the filter cake was washed thoroughly with ether. Concentration in vacuo of the combined filtrate and washes yielded 1.46 g. of a colorless oil. This material was chromatographed on 50 g. of silica gel. Elution with 2:1 parts by volume, 1:1 parts by volume and 1:2 parts by volume hexane-ether afforded 1.38 g. of rac. E-8-benzyloxy-3,7-dimethyl-4-octen-1-ol which was evaporatively distilled giving 1.37 g. (92%) of colorless oil, b.p. 107°-108° C. (bath temperature) (0.03 mm Hg.).

Workup

  1. additionA suspension of 0.432 g
  2. temperaturecooling while a solution of 1.73 g
  3. customat 0°-5° C
  4. customThe cooling bath was removed
  5. additionof saturated sodium sulfate solution was cautiously added with ice bath
  6. temperaturecooling
  7. stirringAfter stirring for 16 hours at room temperature
  8. filtrationthe slurry was filtered on Celite
  9. washthe filter cake was washed thoroughly with ether
  10. concentrationConcentration in vacuo of the combined filtrate and washes
  11. customyielded 1.46 g
  12. customThis material was chromatographed on 50 g
  13. washElution with 2:1 parts by volume, 1:1 parts by volume and 1:2 parts by volume hexane-ether
  14. customafforded 1.38 g
  15. distillationof rac. E-8-benzyloxy-3,7-dimethyl-4-octen-1-ol which was evaporatively distilled
  16. customgiving 1.37 g

Sources & evidence

ORD record
ord-b6546ff2e2014a5f8b2d1ebd98739b1f
Source dataset
uspto-grants-1979_07
Patent number
US04163021

Reaction notes

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