Question

The total number of possible dichloro derivatives of n-butene are:

• A. $2$
• B. $4$
• C. $5$
• D. $6$

Answer 1

The correct option is A $2$

Possible structures of $n-$butene are as follows.

${CH}_2=CH-{CH}_2-{CH}_3\to$ $1-$butene

${CH}_3-CH=CH-{CH}_3\to$ $2-$butene

$\Rightarrow$ Let on chlorination of $1-$butene and $2-$butene the following products (derivatives) are formed.

$\underset{|}{Cl}$ $\underset{|}{Cl}$

${CH}_2=CH-{CH}_2-{CH}_3\stackrel{{Cl}_2}{⟶}{CH}_2-CH-{CH}_2-{CH}_3$

${CH}_3-CH=CH-{CH}_3\stackrel{{Cl}_2}{⟶}{CH}_3-\underset{|}{CH}-\underset{|}{CH}-{CH}_3$

$Cl$ $Cl$

Possible dichloro derivatives of $n-$butene are two.