New method for the synthesis of sym- octahydroxanthenes and sym- octahydrothioxanthenes

-Ketols formed as a result of intramolecular cyclization of 1,5-diketones by alkaline condensation of aldehydes with ketones are converted to 9-R-sym-octahydroxanthenes by the action of acids. Treatment of the -ketols with acids in the presence of hydrogen sulfide leads to the corresponding 9-R-sym-octahydrothioxanthenes. The spectral characteristics of the compounds obtained are given, and some of their properties are described.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1615–1619, December, 1978.