5-position of the heterocycle. The resulting hetarylanalogues of α-benzoins quantitatively isomerize to β-compounds, the (dimethylhydrazono)methylgroup activating the hetaryl residue and thus affording faster isomerization than in their unfunctionalized counterparts. The (dimethylhydrazono)methylgroup is easily convertible into the aldehyde or nitrile group and can also be involved in rehydrazonation