In a recent publication6 the N-substituted 2, &dicyanopiperidines 3a-c were reported to epimerize in hot ethanol, producing mixtures in which two new products (4a-c and 5a-c) could be isolated. Considering the fact that compounds 3a-c and 4a-c are simply alternate chair conformers of the same molecule, these results were questioned. On reexamination of the above reaction with amino nitriles 3a and 3b, it was found that one new product is ...
