The thermal decomposition of organometallic heavy metal trihaloacetates in the presence of olefins

Thermolysis of trimethyltin and triphenyltin trichloroacetates in cyclooctene solution gave 9,9-dichlorobicylo [6.1.0] nonane in moderate yield, and these reactions could also be carried out using smaller amounts of olefin in chlorobenzene or digylme solution. 9,9-Dibromobicyclo [6.1.0] nonane was prepared in 35% yield in similar manner from triphenyltin tribromoacetate. A side reaction also gave benzene in the case of the triphenyltin compounds. The mechanism of these CX₂ transfer reactions was not established, but a process involving decarboxylation and CX₂ transfer from the R₃SnCX₃ intermediate thus formed seems a reasonable possibility. The reaction of phenylmercuric chlorodifluoroacetate and trifluoroacetate with cyclooctene at the reflux temperature gave cyclooctyl chlorodifluoroacetate and trifluoroacetate, respectively, in high yield, as well as benzene and metallic mercury.