想想由大到小排列S、1反应活性次序 CH3 CH3-CH-CH-CH3 CH3-CH2-C-CH3 CH3CH2-CH-CH2 Br CH3 Br CH3 Br ① ② ③ ②>①> ③ 想想 由大到小排列S、2反应活性次序 CH3 CHCH3 CH2Br C-Br Br CH; ① ③ ②>① ③② > ① > ③ 由大到小排列SN1反应活性次序 ① ② ③ ② > ① > ③ CH CH CH3 CH3 CH3 Br CH2 C CH3 CH3 CH3 Br CH3CH2 CH CH2 CH3 Br ① ② ③ 由大到小排列SN2反应活性次序 CHCH3 Br CH2Br C Br CH3 CH3