Some Basic Principles Of Organic Chemistry Question 363
Question: The total number of acylic isomers including the stereoisomers with the molecular formula $ C_4H_7Cl $ [Pb. CET 2004]
Options:
A) 11
B) 12
C) 9
D) 10
Show Answer
Answer:
Correct Answer: B
Solution:
$ C_4H_7Cl $ is a monochloro derivative of $ C_4H_8 $ which itself exists in three isomeric forms.
(i) $ CH_3-CH_2-CH=CH_2 $ : Its possible mono-chloro derivatives are : $ CH_3-CH_2-CH=CH-Cl $ 2 isomers : cis and trans forms $ CH_3-\underset{Cl\ }{\mathop{\underset{|}{\mathop{\overset{\bullet }{\mathop{C}},}},H}},-CH=CH_2 $ optically active (exists in two forms) $ ClCH_2-CH_2-CH=CH_2 $ (one form) $ H_3C-CH_2-\overset{Cl\ }{\mathop{\overset{|}{\mathop{C}},=}},CH_2 $ (one form) (ii) $ CH_3-CH=CH-CH_3 $ : Its possible monochloro derivatives are : $ CH_3-CH=\underset{Cl\ }{\mathop{\underset{|}{\mathop{C}},-}},CH_3 $ Exists in two geometrical forms $ CH_3-CH=CH-CH_2Cl $ Exists in two geometrical forms (iii) $ CH_3-\underset{CH_3\ \ \ \ \ ,}{\mathop{\underset{|}{\mathop{C}},=CH_2}}, $ : Its possible monochloro derivatives are $ CH_3-\underset{CH_3\ \ \ \ }{\mathop{\underset{|}{\mathop{C}},=CH}},-Cl $ Only one form $ ClCH_2-\underset{CH_3\ \ \ \ \ ,}{\mathop{\underset{|}{\mathop{C}},=CH_2}}, $ Only one form Thus, the total acylic isomers forms of $ C_4H_7Cl $ are 12.
