Catalytic hydrogenation of pyrylium salts

On catalytic reduction of 2,6-diphenylpyrylium salts, hydrogenolysis occurs at the C–O bond with the formation of 1,5-diphenylpentanes. The principal direction of the hydrogenation of 9-phenyl-sym-octahydroxanthylium tetrafluoroborate is the formation of a mixture of products of partial and complete reduction of the heterocycle. The structure of the substances obtained was established by IR and¹³C NMR spectroscopy.N. G. Chernyshevskii Saratov State University, Saratov 410026, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 614–617, May, 1998.