Question

What would be the major product for the given electrolysis reaction.

(1)

(2)

(3)

(4) None

Answer 1

Hint: Butene generally contains a chain of 4 carbon atoms having an alkene group when it undergoes an electrolysis process then this type of reactions are known as Kolbe reactions which is also called Kolbe Schmitt Reaction. It is generally an additional reaction.

Complete Step by step solution: Kolbe electrolysis is generally an electrochemical decarboxylation of the salts of carboxylic acid which produces radicals. This reaction is also called as decarboxylative dimerization because it undergoes radical reaction mechanisms. This reaction is used in the synthesis of symmetrical dimers. In the given reaction COOK are given as carboxylic acid salts which undergo through the process of dimerization and it generally follows two step mechanism which is described as:
First of all we know that

Can also be written as

In first step in undergoes through the process of electrolysis and forms radicals as shown below:

But these are not so stable so it readily losses carbon dioxide atoms and from alkyne group which can be represented as:

Product formed is 2-butyne which can also be represented as:

Hence we can say that option 1 is the correct answer.

Note: Radical substitution reaction is a type of reaction which occurs by a free radical mechanism which results in the substitution of one or more of the atoms or groups present in the substrate by different atoms or groups. In the initiation step of radical chain reaction firstly free radical is produced and in terminating step two radicals react together in some way so that the chain can no longer be propagated.