METHYL 2,3-DIBROMO-2,3-DIARYLPROPANOATES - DEBROMINATION AND DEHYDROBROMINATION REACTIONS

Rate and product studies of the iodide- and methoxide-mediated reactio ns of methyl (R,R)- and (R,S)-2,3-dibromo-2,3-diarylpropanoates and so me of their 2- and 3-(4-substitutedphenyl)-derivatives have been carri ed out, The results indicate that the reaction of iodide with most of the substrates affords only debrominated olefins, whereas the course o f the methoxide-promoted reactions seems to depend mainly on the confi guration of the starting substrate. Thus, in the eliminations induced by methoxide ion most of the (R,R)-compounds led exclusively to dehydr obrominated olefins, On the other hand, the dehydrobrominations of mos t of the (R,S)-isomers can be accompanied by debromination, Mechanisti c aspects are discussed.