Question

State which of each of the following compounds will undergo an SN1 and which will undergo SN2 reaction readily?

1) (CH3)3CCH2I

2) (CH3)3CCl

3) (CH3)2CHI

4) (CH3)2CHCH2CH2CH2I

5) (CH3)2CHCH2CH2CH2Cl

Answer 1

1) (CH3)3-C-CH2-Cl will going to form (CH3)3-C-CH2+ if it undergoes and SN1 reaction, which is not stable since it is a primary carbocation

Hence this compound will undergo SN2 reaction, also it is difficult to do SN1 because of presence of bulky group at reverse side

2) (CH3)3-C-Cl will going to form (CH3)3-C+ if it undergoes and SN1 reaction, which is stable since it is a tertiary carbocation

Hence this compound will undergo SN1 reaction

3) SN1 will be more favorable because of secondary carbocation, SN2 can also be done

4) SN2 primary carbocation

5) SN2 primary carbocation