CH3fH—CH2 CH3CH-CH2-CH2 HBr CH Br H CH, CH CH C CHCH3+ HBr CH3-C-CH一CH2H CH3 CH? Br C4以上则难于在室温下开环加HX Br Br. 2 rtC4以上则难于在室温下开环加HX Br 2 rt Br Br