question_answer

Which of the following reactions will not produce a racemic product? [JEE MAIN Held on 09-01-2020 Evening]

A) \[C{{H}_{3}}C{{H}_{2}}CH=C{{H}_{2}}\xrightarrow{HBr}\]

B)

C) \[C{{H}_{3}}-\underset{H}{\mathop{\underset{|}{\mathop{\overset{C{{H}_{3}}}{\mathop{\overset{|}{\mathop{C}}\,}}\,}}\,}}\,-CH=C{{H}_{2}}\xrightarrow{HCl}\]

D) \[C{{H}_{3}}-\overset{O}{\mathop{\overset{||}{\mathop{C}}\,}}\,C{{H}_{2}}C{{H}_{3}}\xrightarrow{HCN}\]

Correct Answer: C

Solution :

\[C{{H}_{3}}-C{{H}_{2}}-\overset{O}{\mathop{\overset{||}{\mathop{C}}\,}}\,-C{{H}_{3}}\xrightarrow{HCN}C{{H}_{3}}-\underset{(Racemic\,\,mixture)}{\mathop{C{{H}_{2}}-\underset{CN}{\mathop{\underset{|}{\mathop{\overset{OH}{\mathop{\overset{|}{\mathop{C}}\,}}\,}}\,}}\,-C{{H}_{3}}}}\,\]\[{{(C{{H}_{3}})}_{2}}CH-CH=C{{H}_{2}}\xrightarrow{HCl}\underset{(Optically\,\,inactive)}{\mathop{{{(C{{H}_{3}})}_{2}}\overset{Cl}{\mathop{\overset{|}{\mathop{C}}\,}}\,-C{{H}_{2}}-C{{H}_{3}}}}\,\] \[C{{H}_{3}}C{{H}_{2}}CH=C{{H}_{2}}\xrightarrow{HBr}C{{H}_{3}}C{{H}_{2}}\underset{Br}{\mathop{\underset{|}{\mathop{C}}\,}}\,\underset{(Racemic\,\,mixture)}{\mathop{H-C{{H}_{3}}}}\,\]