IR Spectra and Structure of Immunoactive 8–Azasteroids in Model Compounds

The IR spectra of biologically active molecules of 8-azasteroids and model compounds in the region of C=O, C=C, C--N, and C--H vibrations (1800–1400 cm−1) have been studied in detail. The structure of compounds containing isostructural and isoelectronic α--acyl--β--aminovinylcarbonyl and α--acyl--β--alkoxyvinylcarbonyl fragments have been analyzed. Interpretation of the structure of the IR spectra and of the specificity of the manifestation of the vibrational modes under consideration in the molecules of a particular class of 8-azasteroids is given. The electronic structure of the molecules under investigation complies with the model of mesomeric tautomerism of the aminovinyldicarbonyl fragment.