Polyfluorobicyclo(2,2,1)heptanes Part VII. Undecafluoro- and 4H-decafluoro-bicyclo(2,2,1)heptane-1-thiol and related bridgehead sulphur compounds

The title compounds have been prepared form 1-lithio-undecafluorobicyclo-(2,2,1)heptane and 1H,4-lithio-decafluorobicyclo(2,2,1)heptane, respectively, and sulphur. The undecafluorothiol was also produced from sulphur and the carbanionic intermediate generated from 1H-undecafluorobicyclo(2,2,1)heptane and potassium t-butoxide in dimethyl sulphoxide (DMSO). The thiols were quite acidic and were fully characterised as their disulphides, methyl thio-ethers and related compounds. A novel elimination of sulphur was observed for the undecafluorothiol under conditions which left the 4H-decafluoro analogue unaffected, another example of the effect of substituents at one bridgehead position on reactivities at the other.