Key Point The carbon, which is bonded with four different atoms/groups is known as chiral carbon. The structure of the given IUPAC names are as follows: (a) 3 -methylhexane C
6
H3
−C
5
H2
−C
4
H2
−
3
CH
|
CH3
−C
2
H2
−C
1
H3
or C3H7−•
H
|
C
|
CH3
−C2H5 (It has one chiral carbon atom, marked with dot.) (b) 2 -methylhexane
6
H3
C−C
5
H2
−C
4
H2
−C
3
H2
2
−
H
|
C
|
CH3
−C
1
H3
It has no chiral carbon atom. (c) 2, 4-dimethyl pentane
5
H3
−C
4
H
|
CH3
−C
3
H2
−C
2
H
|
CH3
−C
1
H3
It has also no chiral carbon atom. (d) 2 -methyl pentane H3
5
C
−C
4
H2
−C
3
H2
−C
2
H
|
CH3
−C
1
H3
It has also no chiral carbon atom. Thus, option (a) is the correct answer.