Abstract Simple bromination of olefins almost invariably yields the trans-1, 2-dibromo- product, and in many cases the corresponding cis-product is an unknown compound. Approaches towards a reagent which will generally, mildly and stereospecifically cis- brominate olefins are now discussed.
![meso-2-exo,3-exo-dibromobicyclo[2.2.1]hept-5-ene-2-endo,3-endo-dicarboxylic anhydride结构式](https://image.chemsrc.com/caspic/232/33140-59-9.png)
