Undecylenic Acid → 1-Dodecyne

HRID 2106975Notes

Reaction equation

HRID 2106975 reaction equation
[CH2:1]=[CH:2][CH2:3][CH2:4][CH2:5][CH2:6][CH2:7][CH2:8][CH2:9][CH2:10][CH2:11][CH3:12].C(O)(=O)CCCCCCCCC=C.[OH-].[K+]>C(O)C>[CH:1]#[C:2][CH2:3][CH2:4][CH2:5][CH2:6][CH2:7][CH2:8][CH2:9][CH2:10][CH2:11][CH3:12]

Participants

5

Reactant 3

HCID 5634Undecylenic AcidHCID 81831-DodeceneHCID 14797Potassium Hydroxide

Product 1

HCID 698211-Dodecyne

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

The procedure for the bromination of 1-dodecene was essentially identical to that for 10-undecenoic acid (Step A), and was carried out on a 0.54 mol scale. Dehydrohalogenation was likewise carried out as in Step A using 250 g of 85% KOH (3.78 mol) and heating under reflux for 22 hours in 1.4 L ethanol. The product was isolated by pouring the cooled reaction mixture into 3L of ice-water slush and extracting with ether. The ether layers were washed and dried as before, evaporated, and the residue distilled. The fraction bp 103-113/25 Torr contained the product (36 g, 40%), which was characterized by spectral data: nmr (CDCl3) 0.9 τ(m, 3 H, CH3), 1.3(m, 16 H, CH2), 1.91(t, J=2.5 Hz, 1H, ≡CH), 2.18 (m, 2H, ≡CCH2); IR (film) 3350 (ν≡CH), 2150(νC≡C).

Workup

  1. temperatureheating
  2. customThe product was isolated
  3. additionby pouring
  4. extractionextracting with ether
  5. washThe ether layers were washed
  6. customdried as before,
  7. customevaporated
  8. distillationthe residue distilled

Sources & evidence

ORD record
ord-fa938b89477940498ac652501b7d8e58
Source dataset
uspto-grants-1990_06
Patent number
US04933114

Reaction notes

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