Unusual Reactions ·Alkene+KMnO4→diol(addition) Benzene KMnO>no reaction. ·Alkene+Brz/CCl4→dibromide(addition) Benzene Br2/CCla>no reaction. With FeCla catalyst,Br2 reacts with benzene to form bromobenzene HBr (substitution!).Double bonds remain. > Chapter 16 5Chapter 16 5 Unusual Reactions • Alkene + KMnO4 → diol (addition) Benzene + KMnO4 → no reaction. • Alkene + Br2 /CCl4 → dibromide (addition) Benzene + Br2 /CCl4 → no reaction. • With FeCl3 catalyst, Br2 reacts with benzene to form bromobenzene + HBr (substitution!). Double bonds remain. =>