Menthone/isomenthone production - from methyl vinyl ketone and mesityl oxide

摘要

A mixt of menthone and isomenthone is produced by slowly adding methyl vinyl ketone to a mixt of excess mesityl oxide and 10-70 wt.% aqs. KOH at between 20 degrees C and the reflux temp and subsequently hydrogenating the piperitenone thus formed. The yields of piperitenone is 68% (known process gives 53-54%), expensive solvents are not used, excess mesityl oxide can be readily recovered, and the process is simple to carry out. The isomethone/menthone mixt has a purity of 98% which is of particular importance when it is to be converted into menthol for pharmaceutical and cosmetic purposes.