Abstract: | 2-Phenyl- and 1,2-diphenylbenzo[b]cyclopenta[e]pyrans were subjected to formylation, nitration, and phenylsufonylation. It was shown by PMR spectroscopy that 2-phenylbenzo[b]cyclopenta[e]pyran undergoes substitution exclusively in the 1 position. The effect of the spatial orientation and the degree of electron-acceptor character of the introduced substituents on the chemical shift of the 9-H proton was studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 902–905, July, 1977. |