Polyfuryl(Aryl)alkanes and their derivatives. 6. Stereochemistry of intramolecular rotations about the C-C+ bonds in aryl(Alkyl)difurylcarbonium ions

It was demonstrated by dynamic ¹H NMR spectroscopy that for difurylmethyl and gem-difurylethyl cations conformational changes are realized through rotation of one of the furan rings, whereas in the case of aryldifurylmethyl cations conformational transformations take place as the simultaneous rotation of two aromatic rings; the correlated rotation of the two furan rings proceeds with smaller energy expenditures.For Communication 5 see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 450–455, April, 1993.