Aziridinyl ketones and their cyclic anils. 7. Solvolysis of 1,2-diaryl-1,1a-dihydroazirino[1,2-a]-quinoxalines

Refluxing of 1,2-diaryl-1,1a-dihydroazirino[1,2-a]quinoxaline in 1-propanol leads to 3-aryl-1-arylmethyl-2-propoxy-1,2-dihydroquinoxalines or to aryl(3-aryl-1-arylmethyl-1,2-dihydroquinoxalin-2-yl) (3-aryl-2-hydroxy-1,2-dihydroquinoxalin-1-yl)methanes. Both processes are due to opening of the C-C bond of the aziridine ring; however, in the first process the ylids formed react with solvent molecules, whereas in the second process dimerization of the ylids with the participation of the water present in the solvent is observed.See [1] for communication 6.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 673–679, May, 1984.     

Structure and spectal properties of cinnamoyl pyrones and their vinylogs

The ¹H-NMR and quantum chemical analysis of the stability of tautomers of cinnamoyl pyrone derivatives and vinylogs has been studied. The relationship between the structure of the most stable tautomer and its spectral properties has been investigated. It has been determined that the tautomer of highest stability (88–100 molar %) has an α-pyrone structure and exhibits a trans-conformation in the cinnamoyl fragment. An intense fluorescence of dyes has been observed in non-polar solvents with cinnamoyl fragments having electron-donating substituents or several double bonds in the polymethine chain. A gradient in solvent polarity resulted in fluorescence quenching which permits the use of the dyes as intensometric fluorometric probes for medium polarity examination.      

General methods for the preparation of 1,2,4,5-tetraoxanes – key structures for the development of peroxidic antimalarial agents

General methods are presented for the preparation of symmetric and asymmetric 1,2,4,5-tetraoxanes, based on peroxidation of carbonyl compounds and their derivatives.