Question

Rearrangement of the carbon skeleton of substrate is possible in which of the following reactions?
${{S}_{N}}1,\text{ }{{S}_{N}}2,\text{ }E1,\text{ }E2,\text{ }E1cB,\text{ }{{S}_{N}}2Th,\text{ }{{S}_{N}}2Ar,\text{ }EAS$ (Electrophilic aromatic substitution), electrophilic addition on alkenes, free radical substitution of alkanes.

Answer 1

Hint : We know that rearrangement reaction is a class of organic reactions, in this class; a molecule’s carbon skeleton undergoes rearrangement to produce a structural isomer of the original molecule. For this question by using fries arrangement we can easily identify the carbon skeleton of the substrate.

Complete Step By Step Answer:
A substituent moves within the same molecule from one atom to another atom frequently. Fries rearrangement is an exciting reaction in organic chemistry. Fries Rearrangement is a rearrangement reaction of organic chemistry in which an aryl ester is converted to a hydroxy aryl ketone with the assistance of aqueous acid and a Lewis acid catalyst. In Fries Rearrangement reaction, an acyl group of the phenolic ester gets transferred to the aryl ring. It is also interesting to observe that Fries rearrangement is selective to ortho and para positions, which means that the acyl group gets attached to the ortho position or para position of the aryl ring.
This particular selectivity of the reaction is managed by making specific changes in the reaction conditions (the reaction conditions include the temperature under which the response is made or the solvent used for the reaction). Rearrangement of the carbon skeleton of substrate is possible only in the reactions which involve the formation of carbocation. So out of these following reactions ${{S}_{N}}1,E1,{{S}_{N}}2\left( AR \right),EAS$ (Electrophilic aromatic substitution), electrophilic addition on alkenes involve the formation of carbocation and hence rearrangement of carbon skeleton is possible.

Note :
Remember that although Fries rearrangement is very useful for some industrial purposes; It has some of these advantages. Primarily the yield we get from the synthesis is low to moderate. There is a possibility that the initially formed Easters