Treatment of N-methyl-5α-conaninium iodides, diversely oxygenated at position 12, with a boiling solution of potassium hydroxide in ethylene glycol most often appears to be a satisfactory method to obtain the title compounds. The latter are free bases of reversed configuration at C-20 with regard to the starting compounds. The conversion is however never complete: the conanine base and an isomer of the normal Hofmann elimination product are always formed, occasionally together with minor degradation products. Comparison of the properties of heteroconan-3β-ols carrying an oxygen function at C-12 with those of the corresponding conan-3β-ols revealed differences which can be used as rules to distinguish the epimers of a pair. Deviations from the generally observed regularities seem to be dependent on the nature of the oxygen function located at C-12.