Some Basic Principles Of Organic Chemistry Question 130
Question: Which of the following compounds is not chiral [AIEEE 2004]
Options:
A) 1-chloro-2-methyl pentane
B) 2-chloropentane
C) 1-chloropentane
D) 3-chloro-2-methyl pentane
Show Answer
Answer:
Correct Answer: A
Solution:
To be optically active the compound or structure should possess chiral or a symmetric centre but in the rest of the structures it is present.
$ \underset{1\text{ chloropentane}}{\mathop{H-\overset{Cl}{\mathop{\overset{|}{\mathop{\underset{H}{\mathop{\underset{|}{\mathop{C}},}},}},}},-\overset{H}{\mathop{\overset{|}{\mathop{\underset{H}{\mathop{\underset{|}{\mathop{C}},}},}},}},-\overset{H}{\mathop{\overset{|}{\mathop{\underset{H}{\mathop{\underset{|}{\mathop{C}},}},}},}},-\overset{H}{\mathop{\overset{|}{\mathop{\underset{H}{\mathop{\underset{|}{\mathop{C}},}},}},}},-\overset{H}{\mathop{\overset{|}{\mathop{\underset{H}{\mathop{\underset{|}{\mathop{C}},}},}},}},-H}}, $
$ \underset{2\text{ chloropentane}}{\mathop{H-\overset{H}{\mathop{\overset{|}{\mathop{\underset{H}{\mathop{\underset{|}{\mathop{C}},}},}},}},-\overset{Cl}{\mathop{\overset{|}{\mathop{\underset{H}{\mathop{\underset{|}{\mathop{C}},}},}},}},-\overset{H}{\mathop{\overset{|}{\mathop{\underset{H}{\mathop{\underset{|}{\mathop{C}},}},}},}},-\overset{H}{\mathop{\overset{|}{\mathop{\underset{H}{\mathop{\underset{|}{\mathop{C}},}},}},}},-\overset{H}{\mathop{\overset{|}{\mathop{\underset{H}{\mathop{\underset{|}{\mathop{C}},}},}},}},-H}}, $
$ \underset{1\text{ chloro -2 methyl pentane}}{\mathop{H-\overset{Cl}{\mathop{\overset{|}{\mathop{\underset{H}{\mathop{\underset{|}{\mathop{C}},}},}},}},-\overset{CH_3}{\mathop{\overset{|,}{\mathop{\underset{H,}{\mathop{\underset{|,}{\mathop{C-}},}},}},}},\overset{H}{\mathop{\overset{|}{\mathop{\underset{H}{\mathop{\underset{|}{\mathop{C}},}},}},}},-\overset{H}{\mathop{\overset{|}{\mathop{\underset{H}{\mathop{\underset{|}{\mathop{C}},}},}},}},-\overset{H}{\mathop{\overset{|}{\mathop{\underset{H}{\mathop{\underset{|}{\mathop{C}},}},}},}},-H}}, $
$ \underset{3\text{ chloro 2 methyl pentane}}{\mathop{H-\overset{H}{\mathop{\overset{|}{\mathop{\underset{H}{\mathop{\underset{|}{\mathop{C}},}},}},}},-\overset{CH_3}{\mathop{\overset{|,}{\mathop{\underset{H,}{\mathop{\underset{|,}{\mathop{C-}},}},}},}},\overset{Cl}{\mathop{\overset{|}{\mathop{\underset{H}{\mathop{\underset{|}{\mathop{C}},}},}},}},-\overset{H}{\mathop{\overset{|}{\mathop{\underset{H}{\mathop{\underset{|}{\mathop{C}},}},}},}},-\overset{H}{\mathop{\overset{|}{\mathop{\underset{H}{\mathop{\underset{|}{\mathop{C}},}},}},}},-H}}, $
