Bromination of isomeric 7,8-dibromobenzobicyclo[2.2.2]octa-2,5-dienes: neighbouring group effect on bromination

摘要

The bromination reactions of isomeric 7,8-dibromobenzobicyclo[2.2.2]octa-2,5-dienes were studied and the possible role of neighbouring groups in rearrangements was investigated. Bromination of endo-cis dibromide 9 gives only the rearranged product 14 while the reaction of the exo-cis-dibromide 11 under the same conditions gives only non-rearranged products 15, 16 and 19. The possible role of substituents in the rearrangements was discussed.