On the Structure of 2,6-Dicyanopiperidines: A Correction

Article abstract of DOI:10.1021/jo00379a012

In a recent publication the N-substituted 2,6-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 formed in each case, having melting point and 1H NMR data identical with those described for compounds 4a and 4b.However, these new products were shown to possess the 2,6-trans configuration as found in 5a and 5b and not the 2,6-cis configuration of the diequatorial products.