Pyridine → (Z)-5-Hexadecenal

HRID 1606302

Reaction equation

HRID 1606302 reaction equation
N1C=CC=[CH:3][CH:2]=1.[CH2:7]([OH:21])[CH2:8][CH2:9][CH2:10][CH2:11][CH2:12][CH2:13][CH2:14]/[CH:15]=[CH:16]\[CH2:17][CH2:18][CH2:19][CH3:20]>C(Cl)Cl.[O-2].[O-2].[O-2].[Cr+6]>[CH:7](=[O:21])[CH2:8][CH2:9][CH2:10]/[CH:11]=[CH:12]\[CH2:13][CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][CH2:19][CH2:20][CH2:2][CH3:3]

Participants

5

Reactant 2

HCID 1049PyridineHCID 5364712Myristoleyl alcohol2×

Product 1

HCID 6430183(Z)-5-Hexadecenal

Reagents, catalysts & solvents 2

HCID 10219390chromium (VI) trioxideCatalystHCID 6344DichloromethaneSolvent2×

Procedure

Chromium trioxide (0.56 g. 5.6 mM) is added to a stirred solution of pyridine (0.90 g. 11.4 mM) in methylene chloride (14 ml). The flask is stoppered with a Drieritefilled tube. The deep red solution is stirred for approximately fifteen minutes at room temperature after which a solution of cis-9-tetradecen-1-ol (0.9 mM) in a small amount of methylene chloride (approximately 0.2 ml) is added rapidly and the mixture stirred for another 15 minutes. The product is recovered by decantation from the tarry precipitate, concentrated in vacuo, and the residue extracted with redistilled petroleum ether (Skelly B). This extract is washed successively with dilute aqueous hydrochloric acid (approximately 1%), brine, dilute aqueous sodium bicarbonate (approximately 5%), and brine (until neutral), then filtered through anhydrous magnesium sulfate and evaporated in vacuo to yield 0.17 g. G.c. analysis showed the product contained cis-9-tetradecen-1-ol in approximately 1:9 ratio to the aldehyde, so the product was chromatographed on Florisil (2.4 cm o.d. × 30 cm; packed up to 25 cm) using redistilled benzene (15 ml fractions). Fractions 4 - 7 are combined. Final yield of alcohol-free cis-9-tetradecenal is 60 mg. In accordance with the foregoing procedure but starting with cis-11-hexadecenal in place of cis-9-tetradecenal, there is obtained crude cis-5-hexadecenal (0.19 g.) and alcohol-free cis-11-hexadecenal (0.10 g.).

Workup

  1. customThe flask is stoppered with a Drieritefilled tube
  2. additionis added rapidly
  3. customThe product is recovered by decantation from the tarry precipitate
  4. concentrationconcentrated in vacuo
  5. extractionthe residue extracted with redistilled petroleum ether (Skelly B)
  6. washThis extract is washed successively with dilute aqueous hydrochloric acid (approximately 1%), brine, dilute aqueous sodium bicarbonate (approximately 5%), and brine (until neutral)
  7. filtrationfiltered through anhydrous magnesium sulfate
  8. customevaporated in vacuo
  9. customto yield 0.17 g
  10. customso the product was chromatographed on Florisil (2.4 cm o.d
  11. distillationusing redistilled benzene (15 ml fractions)

Sources & evidence

ORD record
ord-f7f505706bfe47e9abae36fa954fa603
Source dataset
uspto-grants-1976_04
Patent number
US03952093

Linked notes

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