Editing Organic reaction (section)

==By mechanism==
There is no limit to the number of possible organic reactions and mechanisms.<ref>Is This Reaction a Substitution, Oxidation–Reduction, or Transfer? / N.S.Imyanitov. J. Chem. Educ. '''1993''', 70(1), 14–16.  {{doi|10.1021/ed070p14}}</ref><ref>March, Jerry (1992), ''Advanced Organic Chemistry: Reactions, Mechanisms, and Structure'' (4th ed.), New York: Wiley, {{ISBN|0-471-60180-2}}</ref> However, certain general patterns are observed that can be used to describe many common or useful reactions. Each reaction has a stepwise [[reaction mechanism]] that explains how it happens, although this detailed description of steps is not always clear from a list of reactants alone. Organic reactions can be organized into several basic types. Some reactions fit into more than one category. For example, some substitution reactions follow an addition-elimination pathway. This overview isn't intended to include every single organic reaction. Rather, it is intended to cover the basic reactions.

{| class="wikitable" style="background-color:white;float: center; border-collapse: collapse;margin: 0em 0em"
!Reaction type
!Subtype
!Comment
|-
|rowspan=3|[[Addition reaction]]s
|[[electrophilic addition]]
|rowspan=3| include such reactions as [[halogenation]], [[hydrohalogenation]] and [[Hydration reaction|hydration]].
|-
|valign=top| [[nucleophilic addition]]
|-
|valign=top| [[radical addition]]
|-
|[[Elimination reaction]]
|
|include processes such as [[dehydration reaction|dehydration]] and are found to follow an E1, E2 or [[E1cB elimination reaction|E1cB]] [[reaction mechanism]]
|-
|rowspan=6|[[Substitution reaction]]s
|[[Nucleophilic substitution|nucleophilic aliphatic substitution]]
|with [[SN1 reaction|S<sub>N</sub>1]], [[SN2 reaction|S<sub>N</sub>2]] and [[SNi|S<sub>N</sub>i]] [[reaction mechanism]]s
|-
|[[nucleophilic aromatic substitution]]
|rowspan=5|
|-
|[[nucleophilic acyl substitution]]
|-
|[[electrophilic substitution]]
|-
|[[electrophilic aromatic substitution]]
|-
|[[radical substitution]]
|-
|[[Organic redox reaction]]s
|
|are [[redox reaction]]s specific to [[organic compound]]s and are very common.
|-
|rowspan=3|[[Rearrangement reaction]]s
|[[1,2-rearrangement]]s
|rowspan=3|
|-
|[[pericyclic|pericyclic reactions]]
|-
|[[olefin metathesis|metathesis]]
|}

In [[condensation reaction]]s a small molecule, usually water, is split off when two [[reactant]]s combine in a chemical reaction. The opposite reaction, when water is consumed in a reaction, is called [[hydrolysis]]. Many [[polymerization]] reactions are derived from organic reactions. They are divided into [[addition polymerization]]s and [[step-growth polymerization]]s.

In general the stepwise progression of reaction mechanisms can be represented using [[arrow pushing]] techniques in which curved arrows are used to track the movement of electrons as starting materials transition to intermediates and products.