What are the different types of organic reaction?

Answer 1

Addition Reactions - involve the conversion of a π bond into 2 new σ bonds

General form: A + B → C

Eg. CH3-CH=CH-CH3 + HCl → CH3-CH2-CHCl-CH3

Substitution Reactions - involve the no change in bonding - one σ bond replaces another

General form: A + B → C + D

Eg. CH3-CHBr-CH2-CH3 + KOH(aq) → CH3-CH(OH)-CH2-CH3 + KBr

Elimination Reactions - reverse of addition, in that two σ bonds are lost, replaced by a new π bond

General form: A → B + C

Eg. CH3-CH(OH)-CH2-CH3 -- conc. H2SO4 --> CH3-CH=CH-CH3 + H2O

Rearrangement / Isomerisation - process in which a single substance changes structure, A → B. Such a reaction may involve changes in bond / type, though this is not necessary. These reactions are comparatively rare.

Eg. CH3-CH2-CH2-C(OH)=CH2 → CH3-CH2-CH2-C(=O)-CH3

These are the four "prototypical" reactions, though several others which can be categorised as one of these are generally referred to by other names.

Eg. CH3-CH(OH)-CH3 -- H2SO4 / K2Cr2O7 --> CH3-C(=O)-CH3

could be described as an elimination reaction, but would usually be called an oxidation

Eg. CH3-C(=O)-CH3 -- 1. LiAlH4 2. H^+ / H2O --> CH3-CH(OH)-CH3

could be described as a (nucleophilic) addition reaction, but would usually be called a reduction

Eg. CH3-C(=O)-OH + CH3-OH -- H2SO4 / Δ / reflux --> CH3-C(=O)-O-CH3 + H2O

could be described as a substitution reaction, but would usually be called a condensation

Another important category of organic reactions are straight-forward Lowry-Bronsted acid-base reactions:

Eg. (CH3-CH2)3N + HCl → (CH3-CH2)3NH^+ + Cl^-

Note that there are also some reactions that are difficult to characterise in a simple way, like the following reactions requiring catalysis:

stilbene + ethylene → styrene

C6H5-CH=CH-C6H5 + CH2=CH2 → 2 C6H5-CH=CH2

but-1-yne + water → butanone

CH3-CH2-C≡CH + H2O → CH3-CH2-C(=O)-CH3

(this is actually an addition reaction followed by an isomerisation)

CH3-CH2-C(=O)-CH3 + NH2-OH → CH3-CH2-C(=N-OH)-CH3 + H2O

the pinacol to pinacolone rearrangement

CH3-C(CH3)(OH)-C(CH3)(OH)-CH3 → CH3-C(CH3)2-C(=O)-CH3

which is an elimination reaction that involves an isomerisation

... I add these last few just to illustrate that the general types are a useful tool / guide for understanding organic chemistry, but they are not the be-all and end-all.

Answer 2

The different types of organic reactions include substitution, addition, elimination, oxidation, reduction, condensation, and hydrolysis reactions. These reactions involve the breaking or formation of chemical bonds in organic molecules, resulting in the transformation of reactants into products with different chemical properties.