Retinol → Retinal

HRID 2399009Notes

Reaction equation

HRID 2399009 reaction equation
[CH3:1][C:2]1[CH2:7][CH2:6][CH2:5][C:4]([CH3:9])([CH3:8])[C:3]=1/[CH:10]=[CH:11]/[C:12](/[CH3:21])=[CH:13]/[CH:14]=[CH:15]/[C:16](/[CH3:20])=[CH:17]/[CH2:18][OH:19]>C(Cl)Cl.[O-2].[O-2].[O-2].[Ni+3].[Ni+3]>[CH3:1][C:2]1[CH2:7][CH2:6][CH2:5][C:4]([CH3:8])([CH3:9])[C:3]=1/[CH:10]=[CH:11]/[C:12](/[CH3:21])=[CH:13]/[CH:14]=[CH:15]/[C:16](/[CH3:20])=[CH:17]/[CH:18]=[O:19]

Participants

4

Reactant 1

HCID 445354Retinol

Product 1

HCID 638015RetinalYield 86.1%

Reagents, catalysts & solvents 2

HCID 10313272Nickel oxide (Ni2O3)CatalystHCID 6344DichloromethaneSolvent

Conditions

Temperature
10 °C

Procedure

57.2 g (0.2 mole) of crystalline all-trans vitamin A alcohol are dissolved in 1 liter of methylene chloride. The solution is then stirred at -20° C. to -35° C. in 10 minute intervals with a total of 90 g of nickel peroxide prepared in Example 4 in 5 portions. After the last portion has been introduced, the mixture is stirred for a further 15 minutes at -20° C. to -35° C., filtered off under suction and washed with a total of 1 liter of methylene chloride at -30° C. The residue collected on the filter has the spent nickel peroxide. The methylene chloride solution is subsequently concentrated to a volume of about 500 ml on a rotary evaporator. The residual solution is then treated with 500 ml of n-hexane, again evaporated to 500 ml, again treated with 500 ml of n-hexane and finally concentrated to a volume of 100 ml. The concentrate is cooled to 10° C., seeded with vitamin A aldehyde crystals and then left overnight at -20° C. to completely crystallise out. The crystals are then filtered off under suction, washed with 250 ml of pentane at -20° C. and dried in vacuo at 30° C. in a constant weight. There are obtained 49 g (86%) of vitamin A aldehyde with the expected melting point of 63.5°-65° C. and the UV value E11 = 1750 at 366 nm (hexane).

Workup

  1. additionAfter the last portion has been introduced
  2. filtrationfiltered off under suction
  3. washwashed with a total of 1 liter of methylene chloride at -30° C
  4. customThe residue collected on the filter
  5. concentrationThe methylene chloride solution is subsequently concentrated to a volume of about 500 ml on a rotary evaporator
  6. additionThe residual solution is then treated with 500 ml of n-hexane
  7. customagain evaporated to 500 ml
  8. additionagain treated with 500 ml of n-hexane
  9. concentrationfinally concentrated to a volume of 100 ml
  10. waitleft overnight at -20° C.
  11. customto completely crystallise out
  12. filtrationThe crystals are then filtered off under suction
  13. washwashed with 250 ml of pentane at -20° C.
  14. customdried in vacuo at 30° C. in a constant weight

Sources & evidence

ORD record
ord-4ff69d4ba9a2488abe88f3e0890d6cbf
Source dataset
uspto-grants-1977_05
Patent number
US04026910

Reaction notes

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