注意的几个问题 DHIHBrHCPHF (1l(CH3)2C=CH2>CH3CH=CH2>CH2=CH2 (ⅲi)区域选择性规律:绝大多数情况下符合马尔科夫 尼可夫规律 CH3 CHa HC-C=CH -CH-H H3C-C-CH. Actual H-Br: CH, B B 3° Carbocation fert-Butyl bromide (more stable carbocation This reaction does not occur appreciably: CH3 CHa CHa HC-CCH2米→HC-C-CH2米→HC=CH-CH2= Bri formed H Br: H-Br l° Carbocation Isobutyl bromide (less stable carbocation)注意的几个问题 (i)HI>HBr>HCl>HF (ii)(CH3 )2C=CH2>CH3CH=CH2>CH2=CH2 (iii)区域选择性规律：绝大多数情况下符合马尔科夫 尼可夫规律