Configuration and conformation of 3,5-diphenyl-2-thiabicyclo[4.4.0]decane
The PMR spectra of 3,5-diphenyl-2-thiabicyclo[4.4.0]decane and its 4,6-dideutero derivative and S-oxide in the presence of Eu(dpm)3 were studied. It was established that 3,5-diphenyl-2-thiabicyclo[4.4.0]decane has a cis,cis,cis configuration. The extremal spin-spin coupling constants (SSCC) constitute evidence for conformational rigidity of the investigated condensed system, which exists in the form of a puckered chair. The formation of the same cis,cis,cis isomer of 3,5-diphenyl-2-thiabicyclo[4.4.O]decane in the case of catalytic hydrogenation, disproportionation with trifluoroacetic acid, and ionic hydrogenation constitutes evidence for stereospecificity of the processes involving the reduction of the double bonds in 2,4-diphenyl-5,6-tetramethylene-6H-thiopyran.