By measurement of CH-NH coupling constants at low temperatures, the NH axial conformation was shown to be the dominant, or sole, conformation for tetrahydro-1, 3- oxazine, tetrahydro-2-methyl-1, 3-oxazine, and 1-methyl-1, 3-diazane. These results provide further experimental evidence for the generalized anomeric effect. Nuclear Overhauser experiments established the partial axial character of the N-methyl substituent in ...
