Types of Organic Reaction

The organic reactions are basically classified into eight types and they are:

  1. Substitution Reaction
  2. Addition Reaction
  3. Rearrangement Reaction
  4. Elimination Reaction
  5. Condensation Reaction
  6. Pericyclic Reaction
  7. Isomerisation Reaction
  8. Polymerisation Reaction

Substitution Reaction:

As the name indicates that the substitution is going to take place in between molecules or atoms

Generally it involves in replacement of an atom or a molecule (group of atoms) with another atoms or group of atoms without any change in another part of molecule and the new atom which enters in the molecule is known as the substituent.

The product obtained after substitution is known as substitution product and based on the nature it is classified into three types. They are:

  1. Nucleophilic substitution reaction
  2. Electrophilic substitution reaction
  3. Free radical substitution reaction.


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Here the Chlorine atom is substituted by OCH3 atom.

Addition Reaction:

It involves in the combination of two molecules which gives a single product is called as addition reaction. These reactions contain multiple bonds.


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These reactions are again divided into three types based on attacking species and their nature and they are:

  1. Nucleophilic addition reaction
  2. Electrophilic addition reaction
  3. Free radical addition reaction

Rearrangement Reaction:

In these type of reactions the atoms or group of atoms migrate from one atom to another in the same molecule.

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From the above example we can see that after reacting with H2SO4 cyclohexanixime converted into caprolactum due to rearrangement of atoms in the benzene ring.

Elimination Reaction:

It involves in the loss of two or more atoms from the same or adjacent atoms which leads to the formation of multiple bonds.

Based on the position of elimination of atoms there are three types of reactions

  1. α-Elimination reaction
  2. β-Elimination reaction
  3. γ-Elimination Reactions
Condensation Reaction:

In this reaction without any elimination of atoms or group of atoms they combine to form as a product.

Few examples of condensation reactions are HO, HCl etc.

Pericyclic Reaction:

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The above example is a pericyclic reaction from which we can say that it does not require any catalyst and it can be initiated by heat or light also the bond breaking and making occurs simultaneously.

Isomerisation Reaction:

In this one molecule is transformed into another molecule which has exactly same number of atoms but have different arrangements.

e.g. A-B-C → B-A-C

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Here butane and the 2-methylpropane has same number of atoms but the arrangements are different so as per IUPAC names are also different

Polymerisation Reaction:

It is a process in which monomer molecules react together to form a polymer which has chains or 3-dimensional network.


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