Question

Predict the order of reactivity towards E2dehydrohalogenation of the following compounds:ethyl bromide, n-
propyl bromide, isobutyl bromide, neopentyl bromide.Justify your answer​

Answer 1

Answer: In SN  

2

 reaction, steric factors determine the reactivity. more reactive alkyl halides have less steric hinderance. Hence, the decreasing order of the reactivity of alkyl halides is 1  

o

>2  

o

>3  

o

.

(i)  1-Bromopentane >  2-Bromopentane > 2-Bromo-2-methylbutane

(ii) 1-Bromo-3-methylbutane >  2-Bromo-3-methylbutane >  2-Bromo-2-methylbutane

(iii) 1-Bromobutane >  1-Bromo-3-methylbutane >  1-Bromo-2-methylbutane > 1-Bromo-2, 2-dimethylpropane