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This rearrangement differs from similar isomerizations of carbohydrates, which involve the migration of hydrogen and proceed through discrete enediol intermediates.These include the Lobry–de Bruyn–van Ekenstein transformation, [2] the Heyns [3] and Amadori rearrangements, [4] and the Voight [5] and Bilik [6] reactions. α-hydroxy imines may also undergo the rearrangement, although the ...
In organic chemistry, acyloins or α-hydroxy ketones [1] are a class of organic compounds of the general form R−C(O)CH(OH)−R', composed of a hydroxy group (−OH) adjacent to a ketone group (>C=O). The name acyloin is derived from the fact that they are formally derived from reductive coupling of carboxylic acyl groups (−C(=O)OH). [1]
The net reaction between an aldehyde (or an alpha-hydroxy-ketone) and the copper(II) ions in Benedict's solution may be written as: RCHO + 2 Cu 2+ + 5 OH − → RCOO − + Cu 2 O + 3 H 2 O. The hydroxide ions in the equation forms when sodium carbonate dissolves in water. With the citrate included, the reaction becomes:
Alpha-hydroxy ketones are also called acyloins. [1] They are commonly formed by condensation or reductive coupling of two carbonyl (C=O) compounds or oxidation of ketones. The simplest such compound is hydroxyacetone. If the alcohol is primary, alpha-hydroxy ketones give a positive Fehling's test. Beta-hydroxy ketones are a type of aldol.
Hydroxyacetone can be produced by degradation of various sugars. In foods, it is formed by the Maillard reaction. It reacts further to form other compounds with various aromas. [6] As such it finds some use as a flavoring.
The following examples represent only a small portion of syntheses that highlight the use of the Rubottom oxidation to install an important α-hydroxy functionality. Some of the major features of the following syntheses include the use of buffered conditions to protect sensitive substrates and the diastereoselective installation of the α ...
Tollens' test for aldehyde: left side positive (silver mirror), right side negative Ball-and-stick model of the diamminesilver(I) complex. Tollens' reagent (chemical formula ()) is a chemical reagent used to distinguish between aldehydes and ketones along with some alpha-hydroxy ketones which can tautomerize into aldehydes.
The Buchner–Curtius–Schlotterbeck reaction is the reaction of aldehydes or ketones with aliphatic diazoalkanes to form homologated ketones. [1] It was first described by Eduard Buchner and Theodor Curtius in 1885 [ 2 ] and later by Fritz Schlotterbeck in 1907. [ 3 ]