\( 2 \)-Methyl propyl bromide reacts with \( \mathrm{C_2H_5O^-} \) and gives ‘A’ whereas on reaction with \( \mathrm{C_2H_5OH} \) it gives ‘B’. The mechanism followed in these reactions and the products ‘A’ and ‘B’ respectively are:
\( \mathrm{S_{N}2} \), A = iso-butyl ethyl ether; \( \mathrm{S_{N}1} \), B = tert-butyl ethyl ether
\( \mathrm{S_{N}1} \), A = tert-butyl ethyl ether; \( \mathrm{S_{N}2} \), B = iso-butyl ethyl ether
\( \mathrm{S_{N}1} \), A = tert-butyl ethyl ether; \( \mathrm{S_{N}1} \), B = \( 2 \)-butyl ethyl ether
\( \mathrm{S_{N}2} \), A = \( 2 \)-butyl ethyl ether; \( \mathrm{S_{N}2} \), B = iso-butyl ethyl ether
