Frequencies and intensities of the carbonyl IR absorption bands and structures of cyclopenta [b] chromene derivatives

The integral intensities of the absorption bands of the carbonyl groups (A_C=O) of 2-phenylcyclopentab]chromene derivatives were determined. The A_C=O values and the V_C=O frequencies are proposed as criteria for the determination of the positions of the aldehyde and ketone groups in cyclopentab]chromenes. The applicability of these criteria was confirmed by ¹³C NMR spectroscopy of the carbonyl bonds. A qualitative relationship between the A_C=O values and the ¹³C chemical shifts of the bonds of a number of carbonyl-containing compounds was found.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1030–1034, August, 1980.