CONVERSION OF 3,N-DITHIABICYCLO[N.3.1]ALKATRIENES TO BICYCLO[N.3.1]ALKAPENTAENES

The application of the Ramberg-Backlund reaction in the conversion of several 3,n-dithiabicyclo[n.3.1]alkatrienes to the corresponding bicyclo[n.3.1]alkapentaenes is reported. Proton magnetic resonance and ultraviolet spectra were utilized in the overall characterization of bicyclo[8.3.1]tetradeca-2,8,10,12,1(14)-pentaene, bicyclo[9.3.1]pentadeca-2,9,11,1(15)-pentaene, and their precursors. The final step in the synthesis was a Ramberg-Backlund of a bis-alpha,alpha'-chloro sulfone. The intermediate, 2-chloro-3-thiabicyclo[9.3.1]pentadeca-9,11,13,1(15)-tetraene 3,3-dioxide, was isolated and characterized. The structure and stability of the bridged alpha,alpha'-dichloro sulfide intermediates were examined.