Alkylation of several enamines by phenacyl or p-bromophenacyl bromide oxime affords the corresponding alkylated immonium salts III. Mild hydrolysis of these salts in most cases yields the unknown 6-hydroxy-4,5-dihydro-1,2,4H-oxazines (VI). Spectroscopic observation shows that some of these compounds exist in solution only in the cyclic form, some in a ring-chain tautomeric equilibrium with the corresponding