Ncert Exercises & Solutions

How many alcohols with molecular formula $C_{4} H_{10} O$ are chiral in nature?

1. 1

2. 2

3. 3

4. 4

Hint: If all the substituents attached to the carbon are different then it is called chiral carbon

The three isomers of butanol are possible. Structural formula of these isomers are given below

(i) ${CH}_{3} {CH}_{2} - {CH}_{2} - {CH}_{2} OH$
$Butan - 1 - ol$

No carbon is chiral in this compound as none of the four carbon is bonded to four different substituents.

(ii) $*$
${CH}_{3} - {CH}_{2} - CH - {CH}_{3}$
$|$
$OH$
$Butan - 2 - ol$

In this compound, asterisk marked carbon is chiral carbon as all foursubstituents, attached to it are different.

(iii) ${CH}_{3}$
$|$
$H_{3} C — C — {CH}_{3}$
$|$
$OH$
$2 - methylpropan - 2 - ol$

Here, again carbon is not chiral in nature. So, only one alcohol is chiral in nature and the correct option is (1)