Citronellol → Menthone

Participants

Reaction Steps

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%.

Provenance & Evidence