Pyridine → rac. E-8-benzyloxy-3,7-dimethyl-4-octenal

HRID 1277535Notes

Reaction equation

HRID 1277535 reaction equation
N1C=CC=CC=1.[CH2:7]([O:14][CH2:15][CH:16]([CH3:25])[CH2:17]/[CH:18]=[CH:19]/[CH:20]([CH3:24])[CH2:21][CH2:22][OH:23])[C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1>[O-2].[O-2].[O-2].[Cr+6].ClCCl>[CH2:7]([O:14][CH2:15][CH:16]([CH3:25])[CH2:17]/[CH:18]=[CH:19]/[CH:20]([CH3:24])[CH2:21][CH:22]=[O:23])[C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1

Participants

5

Reactant 2

HCID 1049PyridineHCID 12923303rac. E-8-Benzyloxy-3,7-dimethyl-4-octen-1-ol

Product 1

HCID 12923307rac. E-8-benzyloxy-3,7-dimethyl-4-octenal

Reagents, catalysts & solvents 2

HCID 10219390chromium (VI) trioxideCatalystHCID 6344DichloromethaneSolvent2×

Procedure

To a solution of 1.19 g. of pyridine in 15 ml. of dichloromethane was added0.6 g. (6 mmoles) of chromium trioxide. The brown mixture was stirred at room temperature for 15 minutes, then treated with a solution of rac. E-8-benzyloxy-3,7-dimethyl-4-octen-1-ol (0.262 g.; 1 mmole) in 3 ml. of dichloromethane. After stirring at room temperature for 15 minutes, the dichloromethane solution was decanted from the dark tarry residue then theresidue was washed three times with fresh dichloromethane. The dichloromethane solutions were combined and washed with 1 N aqueous sodiumhydroxide, 1 N aqueous hydrochloric acid, saturated aqueous sodium bicarbonate solution and brine then dried, filtered and concentrated in vacuo. The residue (0.255 g.) was chromatographed on 10 g. of silica gel. Elution with 9:1 parts by volume and 4:1 parts by volume hexane-ether gave0.196 g. (75.5%) of pure rac. E-8-benzyloxy-3,7-dimethyl-4-octenal. Evaporative distillation yielded a colorless liquid, b.p. 90° -93° C. (bath temperature) (0.1 mm Hg.).

Workup

  1. stirringAfter stirring at room temperature for 15 minutes
  2. customthe dichloromethane solution was decanted from the dark tarry residue
  3. washwas washed three times with fresh dichloromethane
  4. washwashed with 1 N aqueous sodiumhydroxide, 1 N aqueous hydrochloric acid, saturated aqueous sodium bicarbonate solution and brine
  5. customthen dried
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo
  8. customThe residue (0.255 g.) was chromatographed on 10 g
  9. washElution with 9:1 parts by volume and 4:1 parts by volume hexane-ether gave0
  10. distillationEvaporative distillation
  11. customyielded a colorless liquid, b.p. 90° -93° C. (bath temperature) (0.1 mm Hg.)

Sources & evidence

ORD record
ord-e84de1cc7d1d4708a49ac90eab22b2c6
Source dataset
uspto-grants-1981_07
Patent number
US04277610

Reaction notes

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