What is Rearrangement reaction?
{{jargon|date=January 2024}} A '''rearrangement reaction''' is an [[organic reaction]] where the [[carbon]] [[wikt:skeleton|skeleton]] of a [[molecule]] is rearranged. The result is a [[structural isomer]] of the original molecule.<ref>{{JerryMarch}}</ref> Often a [[substituent]] moves from one [[atom]] to another atom in the same molecule. In the example below, the substituent R moves from carbon atom 1 to carbon atom 2: [[File:General scheme rearrangement.svg|center|General scheme rearrangement]] [[Intermolecular]] rearrangements also take place. :[[File:IsochorismatePyruvateLyase.svg|Isochorismate Pyruvate Lyase converts Isochorismate into salicylate and Pyruvate]] Sometimes chemists draw [[diagram]]s with [[arrow]]s that show how [[electron]]s are transferred between [[chemical bond|bonds]] during a rearrangement reaction. Many [[organic chemistry]] text books have such diagrams. But they do not tell the full story of the [[reaction mechanism]]. The actual mechanism of a rearrangement with an [[Alkyl|alkyl group]] moving is for the group to slide smoothly along a bond, not [[ionic bond]]-breaking and forming. One example of this is the [[Wagner-Meerwein rearrangement]]: :[[File:Isoborneol2CampheneConversion.svg|Isoborneol Camphene Conversion]] In [[pericyclic reaction]]s, the [[molecular orbital|orbital]] interactions are important. The reactions can not be explained by a series of simple discrete electron transfers. The curved [[arrow]]s showing a [[sequence]] of discrete [[electron transfer]]s can give the same result as a rearrangement reaction. Yet, the diagrams are not necessarily [[realistic]]. In [[allylic rearrangement]], the reaction is [[Ionic bond|ionic]]. Three important rearrangement reactions are [[1,2-rearrangement]]s, [[pericyclic reaction]]s and [[olefin metathesis]]. ==1,2-rearrangements== A 1,2-rearrangement is an organic reaction where a substituent moves from one atom to another atom in a chemical compound. In a 1,2 [[wikt:shift|shift]], the substituent moves between two [[wikt