question_answer

The total number of acylic isomers including the stereoisomers (geometrical and optical), with the molecular formula \[{{C}_{4}}{{H}_{7}}Cl\] is

A)  12                                         

B)  11

C)  10                                         

D)  9

Correct Answer: A

Solution :

                (a) Twelve in all  Six geometrical isomers (i) (ii) (iii) (iv) (v) (vi)  Two optical isomers (vii) \[C{{H}_{3}}-*\overset{Cl}{\mathop{\overset{|}{\mathop{\underset{H}{\mathop{\underset{|}{\mathop{C}}\,}}\,}}\,}}\,-CH=C{{H}_{2}}\] (viii)  \[C{{H}_{3}}-*\overset{H}{\mathop{\overset{|}{\mathop{\underset{Cl}{\mathop{\underset{|}{\mathop{C}}\,}}\,}}\,}}\,-CH==C{{H}_{2}}\]  Four structural isomers (ix) \[C{{H}_{3}}C{{H}_{2}}-\overset{Cl}{\mathop{\overset{|}{\mathop{C}}\,}}\,=C{{H}_{2}}\] (x) \[C{{H}_{3}}-\overset{C{{H}_{3}}}{\mathop{\overset{|}{\mathop{C}}\,}}\,=CHCl\] (xi) \[C{{H}_{3}}-\overset{C{{H}_{2}}Cl}{\mathop{\overset{|}{\mathop{C}}\,}}\,=CHCl\] (xii) \[ClC{{H}_{2}}-C{{H}_{2}}-CH=C{{H}_{2}}\]