Question

Following compounds are given to you :

2-Bromopentane, 2-Bromo-2-methylbutane, 1-Bromopentane

1) Write the compound which is most reactive towards S_N2 reaction.

2) Write the compound which is optically active.

3)  Write the compound which is most reactive towards β-elimination reaction. 

Answer 1

Structure of the given compounds are:

1) As we can see in the above figures, (A), contains the least steric hindrance so towards the S_N2 reaction 1- bromopentane will be most reactive.

2) 2-bromopentane (Figure B) has chiral carbon in it. So, this compound is optically active.

3) Towards the β-elimination 2-bromo-2-methylbutane will be most reactive. Since it will form most stable alkene (on account of highest no. of α-hydrogens).