SYNTHESIS OF TRANS-(+ 7-OCTAPHENYL-3AH,4AH-DICYCLOPENTA[B,E][1,4]DITHIIN BY DIMERIZATION AND FURTHER REARRANGEMENT OF THE TRANSIENT 2,3,4,5-TETRAPHENYL-2,4-CYCLOPENTADIENE-1-THIONE/

Thionation of 2,3,4,5-tetraphenyl-2,4-cyclopentadien-1-one and of 5-di azo-1,2,3,4-tetraphenyl-1,3-cyclopentadiene gives octaphenyl-3aH,4aH-d icyclopenta[b,e]-[1,4]dithiin, most likely by dimerization of the prim arily formed 2,3,4,5-tetraphenyl-2,4-cyclopenladiene-1-thione and subs equent phenyl migration. Characterization has been performed using X-r ay crystallography. Calculations have been performed on derivatives of 2,4-cyclopentadien-1-one and -1-thione.