p-Toluenesulfonic acid → (RS)-2-methyl-5-oxo-2-phenylcyclohexene-1-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

4.4 g (17.6 mmol) of (1 RS,2RS)-1-hydroxy-2-methyl-5-oxo-2-phenylcyclohexane-1-carboxylic acid were heated at reflux for one hour in 100 cm3 of toluene in the presence of 0.34 g of para-toluenesulphonic acid. The reaction mixture was cooled to 0° C. and the precipitate formed was filtered off, washed with ethyl ether and then dried at 50° C. 2.8 g (69%) of (RS)-2-methyl-5-oxo-2-phenylcyclohexene-1-carboxylic acid were thus obtained in the form of a pink solid, the characteristics of which were as follows:

Provenance & Evidence