ORGANIC CHEMISTRY Chapter 21 Mechanism u A slow ast +N ddition imination O O O u N N u 00000O-OO Addition-elimination mechanism(加成一消除机制) Department of Chemistry, Xiamen UniversityORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 21 Mechanism Mechanism L N O O + Nu slow L N O O Nu Nu N O O fast addition elimination L N O O Nu L N O O Nu L N O O Nu L N O O Nu Addition-elimination mechanism (加成－消除 机制)