The Chan rearrangement in organic chemistry is a rearrangement reaction converting an acyloxy acetate in the presence of a strong base to a 2-hydroxy-3-keto-ester ^[1]. Organic chemistry is the scientific study of the structure, properties, composition, reactions, and synthesis of organic compounds that by definition contain carbon. ... A rearrangement reaction is a broad class of organic reactions where the carbon skeleton of a molecule is rearranged to give a structural isomer of the original molecule. ... The common (Arrhenius) definition of a base is a chemical compound that absorbs hydronium ions when dissolved in water (a proton acceptor). ...

The methylene group in the reactant with adjacent carbonyl and acetyl substituents is acidic and can be deprotonated by strong non-nucleophilic bases such as lithium tetramethylpiperidide or lithium diisopropylamide as in an aldol reaction. The thus formed enolate then gives a nucleophilic acyl substitution with the adjacent carbonyl of the acetyl group through a short lived intermediate oxirane. Acidic workup liberates the free hydroxyl group. In chemistry, methylene is a divalent functional group CH2 derived formally from methane. ... In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom. ... Acetyl is the radical of acetic acid. ... In organic chemistry, a substituent is an atom or group of atoms subsituted in place of a hydrogen atom on the parent chain of a hydrocarbon. ... Deprotonation is a chemistry term that refers to the removal of a proton (hydrogen ion H+) from a molecule, forming the conjugate base. ... Lithium tetramethylpiperidide or LiTMP (CAS 38227-87-1) is an organic base and a harpoon base. ... Lithium diisopropylamide (LDA), is a strong base, widely used in organic chemistry for the generation of carbanions. ... An aldol reaction takes the following form: 2 enolate anions ↔ aldol The reaction requires a base catalyst. ... Enol (or, more officially, but less commonly: alkenol) is an alkene with hydroxyl group on one of the carbon atoms of the double bond. ... Nucleophilic acyl substitution is a type of substitution reaction between nucleophiles and acyl compounds. ... In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom. ...

This procedure was rediscovered and employed in the Holton Taxol total synthesis.

External links

• Chan rearrangement @ university of Sussex Link

The University of Sussex is an English campus university located near the East Sussex village of Falmer, near Brighton and Hove and on the edge of the South Downs. ...

References

1. ^  Rearrangement of α-acyloxyacetates into 2-hydroxy-3-ketoesters S. D. Lee, T. H. Chan, and K. S. Kwon Tetrahedron Letters Volume 25, Issue 32 , 1984, Pages 3399-3402 DOI Abstract