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The synthesis of methyl benzoate by Fischer–Speier esterification. Fischer esterification or Fischer–Speier esterification is a special type of esterification by refluxing a carboxylic acid and an alcohol in the presence of an acid catalyst. The reaction was first described by Emil Fischer and Arthur Speier in 1895. [1]
Commonly, the reaction is performed using a solution or suspension of the carbohydrate in the alcohol as the solvent. The carbohydrate is usually completely unprotected. The Fischer glycosidation reaction is an equilibrium process and can lead to a mixture of ring size isomers, and anomers, plus in some cases, small amounts of acyclic forms.
The analogous alkylation of an acetate salt is rarely practiced. The alkylation can be conducted using Mannich bases and the thiocarboxylic acid: CH 3 COSH + R' 2 NCH 2 OH → CH 3 COSCH 2 NR' 2 + H 2 O. Thioesters can be prepared by condensation of thiols and carboxylic acids in the presence of dehydrating agents: [2] [3] RSH + R'CO 2 H → ...
The classic example of a dehydration reaction is the Fischer esterification, which involves treating a carboxylic acid with an alcohol to give an ester RCO 2 H + R′OH ⇌ RCO 2 R′ + H 2 O. Often such reactions require the presence of a dehydrating agent, i.e. a substance that reacts with water.
The classic synthesis is the Fischer esterification, which involves treating a carboxylic acid with an alcohol in the presence of a dehydrating agent: RCO 2 H + R'OH ⇌ RCO 2 R' + H 2 O The equilibrium constant for such reactions is about 5 for typical esters, e.g., ethyl acetate. [ 15 ]
In acid-catalyzed Fischer esterification, the proton binds to oxygens and functions as a Lewis acid to activate the ester carbonyl (top row) as an electrophile, and converts the hydroxyl into the good leaving group water (bottom left). Both lower the kinetic barrier and speed up the attainment of chemical equilibrium.
Fischer indole synthesis; Fischer oxazole synthesis; Fischer peptide synthesis; Fischer phenylhydrazine and oxazone reaction; Fischer glycosidation; Fischer–Hepp rearrangement; Fischer–Speier esterification; Fischer Tropsch synthesis; Fleming–Tamao oxidation; Flood reaction; Folin–Ciocalteu reagent; Formox process; Forster reaction ...
Hermann Emil Louis Fischer FRS FRSE FCS (German pronunciation: [ˈeːmiːl ˈfɪʃɐ] ⓘ; 9 October 1852 – 15 July 1919) was a German chemist and 1902 recipient of the Nobel Prize in Chemistry. He discovered the Fischer esterification. He also developed the Fischer projection, a symbolic way of drawing asymmetric carbon atoms. He also ...