Detectable Epimerization Research Articles

The stereochemistry of the Peters reaction (RSO 2HgX → RHgX)

Thermal decomposition of either exo- or endo-2-norbornylsulfinatomercuric chloride ( exo-A or endo-A) in DMF at 100°C yields only exo-2-norbornylmercuric chloride. Under similar conditions, erythro-3,3-dimethylbutyl-1-sulfinatomercuric chloride-1,2- d 2 yields a 1 1 mixture of erythro- and threo-3,3-dimethylbutyl-1-mercuric chloride-1,2- d 2. endo-2-Norbornylmercuric chloride is not epimirized under the reaction conditions, and endo-A is recovered from partial decompositions without detectable epimerization. These results suggest that the product-forming step proceeds via a stereochemically labile intermediate. Although several qualitative experiments provide evidence against a free radical chain mechanism, the detailed pathway of the reaction has not been established.