DISSOLVING METAL REDUCTION OF CYCLIC KETONES

The reduction of camphor by various alkali metals in liquid ammonia has been repeated and the ratio of epimeric alcohols found to be insensitive to the nature of the metal. The relative rates of reduction of 4-methylcyclobexanone. cyclohexanone, 4-tert-butylcyclohexanone, 4, 4-dimethylcyclohexanone, 3, 3, 5, 5-tetramethylcyclohexanone, fenchone, norcamphor, and camphor with lithium in ammonia in the presence and absence of ethanol have been determined. In the presence of ethanol the 4-substituted cyclohexanones and cyclohexanones are reduced significantly more slowly than the bicyclic ketones. In the absence of ethanol the relative rates are nearly equal. Based on these data and a number of other experiments, a modified mechanism for these reductions is proposed. © 1979, American Chemical Society. All rights reserved.