Question

Arrange the following compounds in increasing order of their reactivity towards SN2 displacement:
\[ \text{2-Bromo-2-methylbutane, 1-Bromopentane, 2-Bromopentane} \]

Hint:

For SN2 reactions, less hindered substrates (primary halides) react faster, while more substituted halides (like tertiary) react slower.

Answer 1

In SN2 reactions, the reactivity increases as steric hindrance decreases. Hence, the increasing order of reactivity is: \[ \text{2-Bromo-2-methylbutane}<\text{2-Bromopentane}<\text{1-Bromopentane} \] This is because 1-Bromopentane, being a primary alkyl halide, has the least steric hindrance.