Reaction of 2-Chlorocyclohexanones with Aluminium Chloridet

Abstract

The reaction of 2-chlorocyclohexanones [A] (2-chlorocyclohexanone and 2-chloro-5-metylcyclohexanone) and 2-chloro-2-alkyl-cyclohexanones [B] (2-chloro-2-metylcyclohexanone, (-) 4-chloromenthone and (±)-1-chlorocarvomenthone) with anhydrous aluminium chloride at 120C under nitrogen has been studied. In the case of CAD, the most quantity of starting material was recovered and a trace amount of the corresponding dechlorinated cyclohexanone was obtained. On the other hand, [B] afforded the corresponding tx, fi-unsaturated ketone in over 60% yield.2, 4-Dichloromenthone afforded thymol under the. same reaction conditions. These results are interpreted as involving formation of the aluminium chloride complex. When pyridine was used instead of aluminium chloride, the corresponding x, 8-unsaturated IratnrIP wprp. nlurnvc nhtninpri from rAi And tm.