Question: In the following sequence of reaction \(C{H_3} - Br\xrightarrow{{KCN}}A\xrightarrow{{{H_3}{O^ + }...

Question

In the following sequence of reaction
$C{H_3} - Br\xrightarrow{{KCN}}A\xrightarrow{{{H_3}{O^ + }}}B\xrightarrow[{LiAl{H_4}}]{{ether}}C$ , the end product $\left( C \right)$ is
$A.$ Acetone
$B.$ Methane
$C.$ Acetaldehyde
$D.$ Ethyl alcohol

Answer 1

Solution

The given sequence of reaction undergoes various types of reaction that is for obtaining product $A$ it undergoes substitution reaction, for obtaining product $B$ it undergoes hydrolysis and for the end product $C$ it undergoes a reduction reaction.

Complete step-by-step answer: In the given question, we have given a multi step reaction and we have asked to determine the end product $C$ . For calculating the end product we have to solve the reaction step by step. This is as follows given below;
Now, first solve for product $A$ , when methyl bromide reacts with potassium cyanide it undergoes substitution reaction that is bromide substituted by cyanide and we get methyl cyanide. Thus we get product $A$ is methyl bromide. The given reaction below represents the overall reaction
$C{H_3} - Br\xrightarrow{{KCN}}C{H_3} - CN + KBr$
For product $B,$
The product $A$ which is methyl cyanide react with ${H_3}{O^ + }$ it undergoes hydrolysis reaction and give rise to carboxylic acid $\left( {C{H_3}COOH} \right)$ . Thus we get the product $B$ is a carboxylic that is known as acetic acid. The given reaction below represents the overall reaction,
$C{H_3} - CN\xrightarrow{{{H_3}{O^ + }}}C{H_3}COOH + HCN$
For product $C,$
The product $B$ which is an acetic acid reaction with $LiAl{H_4}$ in presence of ether it undergoes reduction and forms ethyl alcohol desired product. Thus we get the product $C$ is ethyl alcohol. The given reaction below represents the overall reaction,
$C{H_3}COOH\xrightarrow[{LiAl{H_4}}]{{ether}}{C_2}{H_5}OH + {H_2}O$
Hence, the end product $C$ is ethyl alcohol. So the correct answer is $D.$

Note: It is to be noted that all the given compounds are organic compounds. They have different functional groups attached to it due to different groups present; they have different chemical properties and physical properties.