The Favorskii rearrangement is principally a rearrangement of cyclopropanones and α-halo ketones that leads to carboxylic acid derivatives. In the case of cyclic α-halo ketones, the Favorskii rearrangement constitutes a ring contraction. This rearrangement takes place in the presence of a base, sometimes hydroxide, to yield a carboxylic acid, but usually either an alkoxide base or an amine to yield an ester or an amide, respectively. α,α'-Dihaloketones eliminate HX under the reaction conditions to give α,β-unsaturated carbonyl compounds.[1][2][3][4][5] Note that trihalomethyl ketone substrates will result in haloform and carboxylate formation via the haloform reaction instead.
The Favorskii rearrangement
^Cope, Arthur (1960). Organic Reaction Volume XI (1 ed.). New York: Wiley-Interscience. doi:10.1002/jps.2600500225. ISBN 9780471171270.
^Wohllebe, J.; Garbisch, E. W. (1977). "Ring Contraction via a Favorskii-Type Rearrangement: Cycloundecanone". Organic Syntheses. 56: 107. doi:10.15227/orgsyn.056.0107; Collected Volumes, vol. 6, p. 368.
^Shioiri, Takayuki; Kawai, Nobutaka (1978). "New methods and reagents in organic synthesis. 2. A facile conversion of alkyl aryl ketones to α-arylalkanoic acids using diphenyl phosphorazidate. Its application to a new synthesis of ibuprofen and naproxen, nonsteroidal antiinflammatory agents". J. Org. Chem.43 (14): 2936–2938. doi:10.1021/jo00408a049.
The Favorskiirearrangement is principally a rearrangement of cyclopropanones and α-halo ketones that leads to carboxylic acid derivatives. In the case...
the Russian chemist Alexei Yevgrafovich Favorskii. When the carbonyl is an aldehyde (R"=H), a rearrangement can occur to generate enone, although the...
alternative to the standard Favorskiirearrangement, is to perform what can be thought of as a negative pinacol rearrangement where an anionic group encourages...
into a ketene by loss of dinitrogen with accompanying 1,2-rearrangement. The Wolff rearrangement yields a ketene as an intermediate product, which can undergo...
bromoketone group is converted to ring-contracted carboxylic acid 5 in a Favorskiirearrangement with potassium hydroxide. Next, the thermal decarboxylation takes...
professor for technical chemistry. His discovery of the Favorskiirearrangement in 1894 and the Favorskii reaction between 1900 and 1905 are connected to his...
W X Y Z See also External links 1,2-Wittig rearrangement 1,3-Dipolar cycloaddition 2,3-Wittig rearrangement Acetalisation Acetoacetic ester condensation...
her Doctorate of Philosophy in 1951 for the Application of the Favorskiirearrangement to the problem of angular methylation. Marie Louise Mercury was...
carbonate (CdCO3). Cyclobutanones are the intermediates of the homo-Favorskiirearrangement, and can be isolated when nucleophiles are absent, as in the synthesis...
first artificial sweetener Alexey Favorsky, discoverer of Favorskiirearrangement and Favorskii reaction in organic chemistry Alexander Frumkin, a founder...
The compound can be prepared from 1,3‑dibromo-2‑butanone via the Favorskiirearrangement. Ethyl isocrotonate can be prepared by semihydrogenation of ethyl...
03,6.04,12.05,9]dodeca-2,7-dione (5), which undergoes a pseudo-Favorskiirearrangement in a 25% aqueous solution of sodium hydroxide, giving the dicarboxylic...
first artificial sweetener Alexey Favorsky, discoverer of Favorskiirearrangement and Favorskii reaction in organic chemistry Alexander Frumkin, a founder...
cyclopropylacetylene This mechanism also forms the basis of the Favorskiirearrangement. A related process is the cyclisation of 1,3-dibromopropane via...
lead to α-aryl esters via 1,2-aryl migration. Ring-contractive Favorskiirearrangements may take place under basic conditions (see equation (12) below)...
first artificial sweetener Alexey Favorsky, discoverer of Favorskiirearrangement and Favorskii reaction in organic chemistry Alexander Frumkin, a founder...
p-hydroxyphenacyl PPG (pHP) has been designed to react through a photo-Favorskiirearrangement. This mechanism yields the carboxylic acid as the exclusive photoproduct;...
for a typical ketone. Cyclopropanones are intermediates in the Favorskiirearrangement with cyclic ketones where carboxylic acid formation is accompanied...
okadaic acid biosynthesis. Carbon deletion occurs by way of a Favorskiirearrangement and subsequent decarboxylation. Attack of a ketone in the growing...
core and its formation undergoes a flavoenzyme (EncM) catalyzed Favorskii-like rearrangement of a poly(beta-carbonyl). Studies done on enterocin have shown...
{Cu(OAc)2}}][{\ce {pyridine}}]R-\!{\equiv }\!-\!{\equiv }\!-R}}} In the Favorskii reaction and in alkynylations in general, terminal alkynes add to carbonyl...
Philo T. Farnsworth and Robert L. Hirsch Favorskii reaction, rearrangement – Alexei Yevgrafovich Favorskii Fenton reaction – Henry John Horstman Fenton...
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