Question

$H_{2}C=CH{CH}_{2}Br\underset{}{\overset{NaCN}{\to }}Y\underset{2.H_3{O}^{+}}{\overset{1.C_6{H}_{5}MgBr}{\to }}Z$

Identify product Z in the given reaction sequence:

• A. $H_{2}C=CHC{H}_2\stackrel{O}{\stackrel{||}{C}}{C}_6{H}_5$
• B. $H_{2}C=CHC{H}_{2}NH\stackrel{O}{\stackrel{||}{C}}{C}_6{H}_5$
• C. $H_{2}C=CHC{H}_2\stackrel{OH}{\stackrel{|}{C}}H{C}_6{H}_5$
• D. $H_{2}C=CHC{H}_2\stackrel{N{H}_2}{\stackrel{|}{C}}H{C}_6{H}_5$

Answer 1

Answer: (A)

$H_{2}C=CHC{H}_2\stackrel{O}{\stackrel{||}{C}}{C}_6{H}_5$

$O$

$H_{2}C=CHC{H}_{2}Br\stackrel{NaCN}{\to }{H}_{2}C=CHC{H}_{2}CN\underset{H_3{O}^{+}}{\overset{C_6{H}_{5}MgBr}{\to }}{H}_{2}C=CH-C{H}_2-\stackrel{||}{C}-C_6{H}_5$

First substitution of cyano group takes place in place of bromine and then Grignards reagent is made to react followed by hydrolysis, resulting in the formation of product.

Hence, option $A$ is correct.