■l.Halogenation H H h +Br2 Br HB anhy.AICla Highly selective:Bromination of 3 C CH3 CH3 CH一C-H +Br2 hv CHC-Br HBr CH3 CH3 90%◼Highly selective: Bromination of 3 C 90% CH3 C + HBr CH3 CH3 Br h CH3 C + Br2 CH3 CH3 H RH + Cl 2 RCl + HCl u.v. C Cl l 2 anhy. AlCl 3 ◼ 1. Halogenation + HBr H Br h + Br2 H H