Citronellal → (-)-Menthol

HRID 2423381Notes

Reaction equation

HRID 2423381 reaction equation
[CH3:1][C@H:2]1[CH2:7][C@@H:6]([OH:8])[C@H:5]([C:9]([CH3:11])=[CH2:10])[CH2:4][CH2:3]1.[H][H].CC(=CCCC(CCO)C)C.CC(=CCCC(CC=O)C)C>>[CH3:1][C@H:2]1[CH2:7][C@@H:6]([OH:8])[C@H:5]([CH:9]([CH3:11])[CH3:10])[CH2:4][CH2:3]1

Participants

5

Reactant 4

HCID 7794CitronellalHCID 8842CitronellolHCID 170833(-)-Isopulegol4×HCID 178418361HCID 178418361, compound

Product 1

HCID 16666(-)-Menthol

Conditions

Temperature
80 °C

Procedure

Example 1 was repeated using L-isopulegol with a purity of 97.1% and 84% ee, which was introduced at a rate of 24.5 g/h (total amount 466 g) into the reactor at a hydrogen pressure of 40 bar. The main reactor (MR) was heated to 80° C., the postreactor to 70° C. The L-isopulegol used had the following composition: L-isopulegol: 97.1 GC % by weight, citronellol: 0.05 GC % by weight, citronellal: 0.40 GC % by weight, isopulegol isomer: 0.45 GC % by weight, secondary components: 0.34 GC % by weight. L-menthol (84% ee) was obtained in an amount of 468 g, corresponding to a rate of 24.6 g/h. The chemical purity of the L-menthol output is shown in Table 3.

Workup

  1. customto 70° C

Sources & evidence

ORD record
ord-3b2399e3d69546fd8f55e274afe62d9e
Source dataset
uspto-grants-2011_06
Patent number
US07960593B2

Reaction notes

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