Question

‘D’ in following reaction is?

(1)

(2)

(3)

(4)

Answer 1

The answer here is based on the concept of named reactions and some basic reactions like oxidation and reduction in the organic chemistry part. The final step is the ozonolysis where the cyclic ring opens to form open chain compounds.

Complete step by step answer:
- The concepts of some named reactions that are basics to be known and also some of the general reactions like addition reaction, substitution reaction, elimination reactions, oxidation as well as reductions are familiar to us.
- Let us now deduce the required answer given in the above question which is based on these kinds of reactions.
- Now, in the first step, the given compound that is chloro cyclopentane is treated with dimethyl sulfoxide. This reagent is a good oxidising agent and the bicarbonate ion along with it yields a ketone product. Here, in this reaction, the sulphoxide ion undergoes nucleophilic addition which is then followed by removal of proton by the bicarbonate ion to give ketone that is cyclopentanone(A).
The reaction is as shown below:

In the next step, this compound A is treated with Grignard reagent that adds the methyl group to the ketone where the reaction is as shown below:

This compound formed on further reaction with sulphuric acid, undergoes acidification reaction where dehydration takes place that is elimination of water molecule as shown below:

This compound ‘C’ formed is treated with ozone which undergo oxidation and the zinc in water reacts to form an open chain carbonyl compound as shown below:

So the correct answer is “3”:

Note: Note that ozonolysis is carried out only for the double bonded hydrocarbons. Be thorough with the basic names and the general reactions and also the reagents used for oxidation, reduction and several other types of reaction so that this type of questions can easily be solved.