Reaction #2510564

Reaction equation

L-isopulegol

hydrogen

→

L-menthol

Conditions

Workup

1. 1
   Otherwas operated at a temperature of 50° C.
2. 2
   Otherat 60° C
3. 3
   OtherAll pipelines were provided with electrical trace
4. 4
   Temperatureheating
5. 5
   Othercrystallization of the enantiomerically pure L-menthol (m.p. 44° C.)

Procedure

By means of a centrifugal pump, a circulation was conducted through the main reactor at a rate of about 500 g/h at a feed of L-isopulegol of 24.5 g/h (total amount 588 g) with a purity of 99.8% and 99.8% ee at a constant hydrogen pressure of 30 bar. The main reactor was operated at a temperature of 50° C. and the postreactor at 60° C. All pipelines were provided with electrical trace heating to prevent crystallization of the enantiomerically pure L-menthol (m.p. 44° C.). L-menthol (99.8% ee) was obtained in an amount of 597 g, corresponding to a rate of 24.9 g/h. The product thus obtained was analyzed by gas chromatography. The results are compiled in Table 4.

Source