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The name acyloin is derived from the fact that they are formally derived from reductive coupling of carboxylic acyl groups (−C(=O)OH). [1] They are one of the two main classes of hydroxy ketones , distinguished by the position of the hydroxy group relative to the ketone; in this form, the hydroxy is on the alpha carbon , explaining the ...
Alpha- and beta-hydroxy ketones. In organic chemistry, a hydroxy ketone (often referred to simply as a ketol) is a functional group consisting of a ketone (>C=O) flanked by a hydroxyl group (−OH). Chemicals in this group can be classified by the position of the hydroxyl relative to the ketone.
Hydroxyacetone, also known as acetol, is the organic chemical with the formula CH 3 C(O)CH 2 OH. It consists of a primary alcohol substituent on acetone. It is an α-hydroxyketone, also called a ketol, and is the simplest hydroxy ketone structure. It is a colorless, distillable liquid.
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:
Although examples of enantioselective α-ketol rearrangements starting from achiral α-hydroxy ketones are fairly limited, a number of examples of 1,2-asymmetric induction (due to stereoelectronic factors) have been observed. In one example of an enantioselective process, use of nickel(II) diacetoacetonate and pybox provided 4 in 34% ee. [11] (4)
The Dakin oxidation (or Dakin reaction) is an organic redox reaction in which an ortho- or para-hydroxylated phenyl aldehyde (2-hydroxybenzaldehyde or 4-hydroxybenzaldehyde) or ketone reacts with hydrogen peroxide (H 2 O 2) in base to form a benzenediol and a carboxylate. Overall, the carbonyl group is oxidised, whereas the H 2 O 2 is reduced.
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 ...
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 ]