Editing Ylide (section)

===Sigmatropic rearrangements===
Many ylides react in [[sigmatropic reaction]]s.<ref>{{cite journal |first1=J. B. |last1=Sweeney | title=Sigmatropic rearrangements of 'onium' ylides | journal=[[Chemical Society Reviews]] |year=2009 |volume=38 |issue=4 |pages=1027–1038 |doi=10.1039/b604828p |pmid=19421580}}</ref> The [[Sommelet-Hauser rearrangement]] is an example of a [2,3]-sigmatropic reaction. The [[Stevens rearrangement]] is a [1,2]-rearrangement.

A {{bracket|3,3}}-sigmatropic reaction has been observed in certain phosphonium ylides.<ref name=Ferguson>{{cite journal |last1=Ferguson |first1=Marcelle L. |last2=Senecal |first2=Todd D. |last3=Groendyke |first3=Todd M. |last4=Mapp |first4=Anna K. |year=2006 |title=<nowiki>[3,3]</nowiki>-Rearrangements of Phosphonium Ylides |journal=[[J. Am. Chem. Soc.]] |volume=128 |issue=14 |pages=4576–4577 |doi=10.1021/ja058746q |pmid=16594686}}</ref><ref>(i) Reaction of [[allyl alcohol]] with 2-chloro-5,5-dimethyl-1,3,2-dioxaphosphorinane forms a [[phosphite ester]]. (ii) [[Metal carbene]] addition (from [[ethyl diazoacetate]] and [[ClFeTPP]]) forms an ylide. (iii) A rearrangement reaction (in blue) yields a [[phosphonate]].</ref>

:[[Image:Phosphoniumylide rearrangement.png|400px|Scheme 1. Phosphonium ylide rearrangement]]