Citronellol → Menthone

HRID 2163482Notes

Reaction equation

HRID 2163482 reaction equation
[CH3:1][C:2](=[CH:4][CH2:5][CH2:6][CH:7]([CH2:9][CH2:10][OH:11])[CH3:8])[CH3:3]>[O-2].[Cr+3].[Cu+2]>[CH3:8][C@H:7]1[CH2:9][C:10](=[O:11])[C@H:4]([CH:2]([CH3:3])[CH3:1])[CH2:5][CH2:6]1

Participants

3

Reactant 1

HCID 8842Citronellol

Product 1

HCID 26447Menthone

Reagents, catalysts & solvents 1

HCID 131711404Copper-chromium oxideCatalyst

Procedure

156 g of purified citronellol ([α]D20 = +2.3) was reacted with 7.8 g of copper-chromium oxide (CuO:Cr2O3 = 50:50) at 260° C for 2 hours under a hydrogen pressure of 2.5 kg/cm2.G to afford menthone (menthone 59 wt%, iso-menthone 41 wt%). The product was converted to the enol acetate having a specific rotation, [α]D20, of +55. The optical purity of the product was 80% of that of the starting material. The product was hydrogenated in the same manner as described in Example 4. From the resulting menthol mixture, menthol was isolated. The menthol had a specific rotation, [α]D20, of +39 and an optical purity of 80%.

Sources & evidence

ORD record
ord-cf2addfa88a24fdda0a7bc54d7fb4bef
Source dataset
uspto-grants-1979_01
Patent number
US04134919

Reaction notes

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