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In chemistry, the haloform reaction (also referred to as the Lieben haloform reaction) is a chemical reaction in which a haloform (CHX 3, where X is a halogen) is produced by the exhaustive halogenation of an acetyl group (R−C(=O)CH 3, where R can be either a hydrogen atom, an alkyl or an aryl group), in the presence of a base.
The reaction is named after the German chemist Alfred Wohl (1863–1939). The Wohl degradation. Let's say we have a kiliani-fischer synthesis, it basically removes the row of the C2 carbon, it shortens the carbon chain by one carbon. In one modification, [2] [3] d-glucose is converted to the glucose oxime by reaction with hydroxylamine and ...
Glucose can be shortened by oxidation and decarboxylation to generate arabinose, a reaction known as the Ruff degradation. [1] To increase the glucose carbon chain, a series of chemical reactions can be used to add one more carbon at the aldehyde end of glucose; this process is known as the Kiliani–Fischer synthesis. [2]
This makes the remaining hydrogens more acidic. In the case of methyl ketones, this reaction often occurs a third time to form a ketone trihalide, which can undergo rapid substitution with water to form a carboxylate (−C(=O)O −) in what is known as the haloform reaction. [1]
Ruff degradation is a reaction used to shorten the open chain forms of monosaccharides. [1] It is functionally the reverse reaction of Kiliani-Fischer synthesis. In 1898, Otto Ruff published his work on the transformation of D-Glucose to D-Arabinose later called the Ruff degradation. In this reaction, D-Glucose is converted to D-Arabinose.
The overall reaction for the breakdown of glycogen to glucose-1-phosphate is: [1] glycogen (n residues) + P i ⇌ glycogen (n-1 residues) + glucose-1-phosphate. Here, glycogen phosphorylase cleaves the bond linking a terminal glucose residue to a glycogen branch by substitution of a phosphoryl group for the α[1→4] linkage. [1]
Bromoform was discovered in 1832 by Löwig who distilled a mixture of bromal and potassium hydroxide, as analogous to preparation of chloroform from chloral. [5]Bromoform can be prepared by the haloform reaction using acetone and sodium hypobromite, by the electrolysis of potassium bromide in ethanol, or by treating chloroform with aluminium bromide.
A hypohalite is an oxyanion containing a halogen in oxidation state +1. [citation needed] This includes hypoiodite, hypobromite and hypochlorite. In hypofluorite (oxyfluoride) the fluorine atom is in a −1 oxidation state. Hypohalites are also encountered in organic chemistry, often as acyl hypohalites (see the Hunsdiecker reaction).