In general, the anhydt. 0 compounds derived from reactive, unhindered ketones proved to be oxazolidines, while corresponding compounds obtained from the sterically hindered diisobutyl ketone were azomethines. Interconversion of the two forms was evident for the condensation product of methyl propyl ketone with ethanolamine, which rapidly established an equilibrium between the two structures (I 11) by ring-chain tautomerism. In other cases ...
