Question

How many products are formed in the given reaction?

Answer 1

Hint: In order to solve the above reaction, we need to know about the pinacol-pinacolone rearrangement. It is the important process used for the conversion of $ 1 $ , $ 2 $ diols into carbonyl compounds.

Complete Step By Step Answer:
Let’s first completely understand about a very important process in organic chemistry which is named as pinacol-pinacolone rearrangement. It is the process used for the conversion of $ 1 $ , $ 2 $ diols into carbonyl compounds containing a carbon oxygen double bond. This rearrangement is done via $ 1 $ , $ 2 $ - migration which takes place under acyl conditions. This rearrangement involves the shift of the two adjacent atoms.
Pinacol is a compound that has two hydroxyl groups, each group is attached to a vicinal carbon atom. It appears like a white organic compound. Pinacolone is a ketone that has an odour like camphor and appears like a colourless liquid.
In the given above reaction, it indicates that it is an example of pinacol-pinacolone rearrangement. Here the number of products formed is two. The migratory aptitude of an aryl group is more than that of hydrogen atom or alkyl group. The products formed is shown below:
The first product is this:

The second product is as follows:

Note:
It must be remembered that this rearrangement process is very important in organic chemistry for the conversion of $ 1 $ , $ 2 $ diols into carbonyl compounds. This reaction was first prescribed by the German chemist William Rudolph Fittig in the year $ 1860 $ . Also, this rearrangement proceeds through the formation of an intermediate which is positively charged. The methyl group in the intermediate proceeds to migrate from one carbon atom to another.