Benzene → Ethyl 3,7,11-trimethyldodeca-2,6,10-trienoate

HRID 1112622Notes

Reaction equation

HRID 1112622 reaction equation
[Na].[CH2:2]([OH:4])[CH3:3].[CH2:5]([CH2:15][C:16](=O)[CH3:17])/[CH:6]=[C:7](/[CH2:9][CH2:10][CH:11]=[C:12]([CH3:14])[CH3:13])\[CH3:8].[CH:19]1[CH:24]=CC=CC=1.[OH2:25]>>[CH2:2]([O:4][C:24](=[O:25])[CH:19]=[C:16]([CH3:17])[CH2:15][CH2:5][CH:6]=[C:7]([CH3:8])[CH2:9][CH2:10][CH:11]=[C:12]([CH3:14])[CH3:13])[CH3:3]

Participants

6

Reactant 5

HCID 241BenzeneHCID 702EthanolHCID 962WaterHCID 1549778GeranylacetoneHCID 5360545Sodium

Product 1

HCID 549655Ethyl 3,7,11-trimethyldodeca-2,6,10-trienoateYield 81%

Procedure

Sodium (12 g.) was dissolved in 192 ml. of ethanol and to this solution was added dropwise 60.5 g. of geranylacetone and 102.4 g. of triethylphosphonoacetate in 240 ml. of benzene. The reaction mixture was stirred overnight, then poured over 180 g. of ice and 180 ml. of water. The resulting mixture was extracted twice with 70 ml. of benzene. The organic phases were washed with H2O, dried over MgSO4 and concentrated under reduced pressure. Vacuum distillation gave 66.6 g. (81% yield) of ethyl-3,7,11-trimethyldodeca-2,6,10-trienoate having at C2C3, E/Z ≃ 4.25 and at C6C7, E/Z ≃ 1.5; b.p. 160°-165° C. (0.25 mmHg); 81% yield based on geranyl acetone. This ester was hydrolyzed by the procedure to Example 1 to 3,7,11-trimethyldodeca-2,6,10-trienoic acid having at C2C3E/Z ≃ 3.5 and at C6C7E/Z ≃ 1.5, b.p. 175° C. (1 mm). Yield 46.2 g. (86% based on the ester).

Workup

  1. additionpoured over 180 g
  2. extractionThe resulting mixture was extracted twice with 70 ml
  3. washThe organic phases were washed with H2O
  4. dry with materialdried over MgSO4
  5. concentrationconcentrated under reduced pressure
  6. distillationVacuum distillation
  7. customgave 66.6 g

Sources & evidence

ORD record
ord-fa641c31f75d422c9c58a413a0c5f6b9
Source dataset
uspto-grants-1978_10
Patent number
US04123465

Reaction notes

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