(1R,1R')-2-exo-Mercapto-2'-thioxo-3-exo,3'-exo-bibornane, 2-Dehydro-2,2'-exo-epidithio-3,3'-bibornane and 2-endo,2'- exo-Epidithio-3,3'-bibornanylidene. Potential Antiviral Agents

The compounds 2,2'-exo-epidithio-1,1',7,7,7',7'-hexamethyl-3,3'-bibicyclo[2.2.1]hept-2-ene, C₂₀H₃₀S₂, (2), and 2-endo,2'-exo-epidithio-1,1',7,7,7',7'-hexamethyl-3,3'-bibicyclo[2.2.1] heptanylidene, C₂₀H₃₀S₂, (3), were prepared as potential antiviral agents and their structures were determined by X-ray diffraction. It has been shown previously, that there is a relationship between the strain energy of a C-S-S-C group, as measured by its planarity and the S-S bond length, and the antiviral activity of the compound containing this group. In general, the activity increases with the planarity of the group and as the disulfide bond distorts from a `normal' length. The values of the C-S-S-C torsion angle and S-S bond length for (2) and (3) are 56.1 (1)°, 2.056 (1) Å and 44.9 (2)°, 2.019 (2) Å, respectively. (1R,1R')-2'-exo-mercapto-1,1',7,7,7',7'-hexamethyl-3-exo,3'-exo-bibicyclo[2.2.1]heptane-2-thione, C₂₀H₃₂S₂, (1), is the intermediate compound necessary to obtain compound (2). The absolute configuration of each of the compounds was determined from the X-ray studies.

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