Trifluoroacetic acid → Citronellal

HRID 2174408Notes

Reaction equation

HRID 2174408 reaction equation
[CH3:1][C:2](=[CH:4][CH2:5][CH2:6][C:7](=[CH:9][CH:10]=[O:11])[CH3:8])[CH3:3].FC(F)(F)C(O)=O.[H][H]>[Pd].S([O-])([O-])(=O)=O.[Ba+2].C(O)(C)(C)C>[CH3:1][C:2](=[CH:4][CH2:5][CH2:6][CH:7]([CH2:9][CH:10]=[O:11])[CH3:8])[CH3:3]

Participants

6

Reactant 3

HCID 6422Trifluoroacetic acidHCID 88433,7-Dimethylocta-2,6-Dienal3×HCID 178418361HCID 178418361, compound

Product 1

HCID 7794Citronellal

Reagents, catalysts & solvents 2

HCID 16218511Pd barium sulfateCatalystHCID 6386tert-ButanolSolvent

Procedure

In a 3-L reaction flask were added 500.0 g (3.28 mol) of citral, 2.50 g (0.5 wt % based on the citral) of 5 wt. % Pd/barium sulfate, 10.0 g (22.9 mmol, 2.0 wt % based on the citral) of (2R,4R)-2-(bis-(4′-t-butylphenyl)methyl)-4-(ethylcarbamoyloxy)pyrrolidine, 2.6 g (22.9 mmol) of trifluoroacetic acid, and 500 mL of 10 wt % hydrous t-butanol in a nitrogen atmosphere. The resulting mixture was stirred and the atmosphere was exchanged with a hydrogen atmosphere (0.1 MPa (atmospheric pressure)). After stirring at 60° C. for 21 hours, the catalyst was filtered off and the residue was analyzed using gas chromatography. As a result, it was found that a conversion ratio from citral to citronellal was 99.4% and an optical purity was 90.9% e.e. The crude-citronellal thus obtained was distilled to obtain 398 g (2.58 mol, yield: 78.6%) of d-citronellal having a purity of 98%.

Workup

  1. stirringAfter stirring at 60° C. for 21 hours
  2. filtrationthe catalyst was filtered off

Sources & evidence

ORD record
ord-9c6481811afb455190d96b0ecd057337
Source dataset
uspto-grants-2015_06
Patent number
US09061959B2

Reaction notes

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