The Achmatowicz reaction, also known as the Achmatowicz rearrangement, is an organic synthesis in which a furan is converted to a

dihydropyran In organic chemistry, dihydropyran refers to two heterocyclic compounds with the formula C5H8O: * 3,4-Dihydro-2''H''-pyran *3,6-dihydro-2''H''-pyran Nomenclature In IUPAC names, "dihydro" refers to the two added hydrogen atoms needed to remove o ...

. In the original publication by the Polish Chemist Osman Achmatowicz Jr. (b. 20 December 1931 in

Vilnius Vilnius ( , ; see also other names) is the capital and largest city of Lithuania, with a population of 592,389 (according to the state register) or 625,107 (according to the municipality of Vilnius). The population of Vilnius's functional urb ...

) in 1971

furfuryl alcohol Furfuryl alcohol is an organic compound containing a furan substituted with a hydroxymethyl group. It is a colorless liquid, but aged samples appear amber. It possesses a faint odor of burning and a bitter taste. It is miscible with but unstable ...

is reacted with

bromine Bromine is a chemical element with the symbol Br and atomic number 35. It is the third-lightest element in group 17 of the periodic table ( halogens) and is a volatile red-brown liquid at room temperature that evaporates readily to form a simi ...

in methanol to 2,5-dimethoxy-2,5-dihydrofuran which rearranges to the

with dilute sulfuric acid. Additional reaction steps, alcohol

protection Protection is any measure taken to guard a thing against damage caused by outside forces. Protection can be provided to physical objects, including organisms, to systems, and to intangible things like civil and political rights. Although th ...

with methyl orthoformate and boron trifluoride) and then ketone reduction with

sodium borohydride Sodium borohydride, also known as sodium tetrahydridoborate and sodium tetrahydroborate, is an inorganic compound with the formula Na BH4. This white solid, usually encountered as an aqueous basic solution, is a reducing agent that finds applica ...

produce an intermediate from which many monosaccharides can be synthesised. : The Achmatowitz protocol has been used in

total synthesis Total synthesis is the complete chemical synthesis of a complex molecule, often a natural product, from simple, commercially-available precursors. It usually refers to a process not involving the aid of biological processes, which distinguishes i ...

, including those of desoxoprosophylline, pyrenophorin Recently it has been used in

diversity oriented synthesis In chemistry a divergent synthesis is a strategy with the aim to improve the efficiency of chemical synthesis. It is often an alternative to convergent synthesis or linear synthesis. In one strategy divergent synthesis aims to generate a library ...

: and in enantiomeric scaffolding.Reagents: benzyl chloroformate protects amine as Cbz group, Achmatowitz reaction with m-CPBA, complexation with a molybdenum compound, Cp is

cyclopentadienyl anion In chemistry, the cyclopentadienyl anion or cyclopentadienide is an aromatic species with a formula of and abbreviated as Cp−. It is formed from the deprotonation of the molecule cyclopentadiene. Properties The cyclopentadienyl anion i ...

References

{{DEFAULTSORT:Achmatowicz Reaction Organic reactions Name reactions