Propiolic Acid → 7-Methyl-7-octen-2-ynoic acid

HRID 444417Notes

Reaction equation

HRID 444417 reaction equation
[C:1]([OH:5])(=[O:4])[C:2]#[CH:3].C([Li])(C)(C)C.CN(P(N(C)C)(N(C)C)=O)C.Br[CH2:23][CH2:24][CH2:25][C:26]([CH3:28])=[CH2:27]>CCOCC.[OH-].[Na+].CCOCC>[CH3:28][C:26](=[CH2:27])[CH2:25][CH2:24][CH2:23][C:3]#[C:2][C:1]([OH:5])=[O:4]

Participants

7

Procedure

0.13 Gram (1.85 mmol) propiolic acid is dissolved in 20 ml ether, under nitrogen, and the solution is cooled to -70°. 3.3 Milliliters of 1.1 M t-butyllithium (3.63 mmol) is added over a period of 1 hr, and the mixture is stirred for an additional hour at -60°. HMPA (10 ml) is added, followed by 0.32 g (1.96 mmol) 1-bromo-4-methyl-4-pentene (prepared as in either Example 1 or Example 3), keeping the solution cold. After 24 hr, the mixture is heated to 40°-45°. After 3 days, the reaction is worked up in 5% NaOH/ether, and the aqueous layer is extracted with ether. The basic phase is acidified with HCl and extracted with ether (2×). The latter ether phases are washed with water and brine, dried over Na2SO4, filtered and the solvent is removed to yield 7-methyl-7-octen-2-ynoic acid.

Workup

  1. temperaturethe solution is cooled to -70°
  2. customprepared as in either Example 1 or Example 3),
  3. temperaturethe mixture is heated to 40°-45°
  4. waitAfter 3 days
  5. extractionthe aqueous layer is extracted with ether
  6. extractionextracted with ether (2×)
  7. washThe latter ether phases are washed with water and brine
  8. dry with materialdried over Na2SO4
  9. filtrationfiltered
  10. customthe solvent is removed

Sources & evidence

ORD record
ord-c78976aeeb4f464abf7af1ed08fee0ca
Source dataset
uspto-grants-1981_04
Patent number
US04264518

Reaction notes

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