Question

1.cH3C(+)CH=CH2 2.CH2=CHCH2C(+)H2 3.CH3-HC=CH-CH2 4.(CH3)2C(

Answer 1

1.CH3C(+)CH=CH2 2.CH2=CHCH2C(+)H2 3.CH3-HC=CH-C(+)H2 4.(CH3)2C(+)CH=CH2 正碳离子稳定性次序

正碳离子稳定性次序

4.(CH3)2C(+)CH=CH2>

1.CH3C(+)CH=CH2 >

3.CH3-HC=CH-C(+) H2>

2.CH2=CHCH2C(+)H2

从共轭效应与超共轭效应强度判断.4,1,3有共轭效应,2无；超共轭效应4>1>3.