Abstract peri-Amino-substituted methyl and aryl ketones of the acenaphthene and acenaphthylene series were subjected to protonation and acylation at the nitrogen atom, dehydrogenation, and reactions with aldehydes. Conformations of substituents in the peri positions and probability for their participation in intra-and intermolecular transformations were determined on the basis of spectral data and quantum-chemical calculations.