Question

Which one of the following compound is most reactive for E1 reaction?

• A. $C{H}_3-C{H}_2-\stackrel{Br}{\stackrel{|}{\underset{C{H}_3}{\underset{|}{C}}}}-C{H}_3$
• B. $C{H}_3-C{H}_2-\stackrel{Br}{\stackrel{|}{\underset{C{H}_3}{\underset{|}{C}}}}-C_6{H}_5$
• C. $C{H}_3-C{H}_2-\stackrel{Br}{\stackrel{|}{\underset{C{H}_3}{\underset{|}{C}}}}-C_2{H}_5$
• D. $C{H}_3-C{H}_2-\stackrel{Br}{\stackrel{|}{CH}}-C{H}_3$

Answer 1

The correct option is B $C{H}_3-C{H}_2-\stackrel{Br}{\stackrel{|}{\underset{C{H}_3}{\underset{|}{C}}}}-C_6{H}_5$

$Br$ $C{H}_3$

$C{H}_3-C{H}_2-\underset{|}{\stackrel{|}{C}}-C_6{H}_5⟶C{H}_3-CH=\stackrel{|}{C}-C_6{H}_5$

$C{H}_3$

Here, most stable product has the most reactive $E_1$. Here, the product is stabilized through resonance and in conjugation with the Benzene ring.