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The Criegee oxidation is a glycol cleavage reaction in which vicinal diols are oxidized to form ketones and aldehydes using lead tetraacetate. It is analogous to the use of periodate (Malaprade reaction) but uses a milder oxidant. This oxidation was discovered by Rudolf Criegee and coworkers and first reported in 1931 using ethylene glycol as ...
In organic chemistry, the Malaprade reaction or Malaprade oxidation is a glycol cleavage reaction in which a vicinal diol is oxidized by periodic acid or a periodate salt to give the corresponding carbonyl functional groups. [1] [2] The reaction was first reported by Léon Malaprade in 1928. [3] [4] Amino alcohols are also cleaved. [5]
Glycol cleavage is a specific type of organic chemistry oxidation. The carbon–carbon bond in a vicinal diol (glycol) is cleaved and instead the two oxygen atoms become double-bonded to their respective carbon atoms. Depending on the substitution pattern in the diol, these carbonyls will be ketones and/or aldehydes. [1]
For academic research and pharmaceutical areas, vicinal diols are often produced from the oxidation of alkenes, usually with dilute acidic potassium permanganate or Osmium tetroxide. [8] Osmium tetroxide can similarly be used to oxidize alkenes to vicinal diols.
IBX is notable for oxidizing vicinal diols (or glycols) to diketones without cleavage of the carbon-carbon bond, [10] but oxidative cleavage of glycols to two aldehydes or ketones can occur when modified conditions are used (elevated temperatures or trifluoroacetic acid solvent).
The largest scale oxidation of 1,2-diols gives glyoxal from ethylene glycol. The conversion uses air or sometimes nitric acid. [2] In the laboratory, vicinal diols suffer oxidative breakage at a carbon-carbon bond with some oxidants such as sodium periodate (NaIO 4), (diacetoxyiodo)benzene (PhI(OAc) 2) [9] or lead tetraacetate (Pb(OAc) 4 ...
Dihydroxylation is the process by which an alkene is converted into a vicinal diol.Although there are many routes to accomplish this oxidation, the most common and direct processes use a high-oxidation-state transition metal (typically osmium or manganese).
In extreme cases the periodate may be exchanged for lead tetraacetate which reacts in a similar manner and is soluble in organic solvents (Criegee oxidation). Periodate cleavage is often utilized in molecular biochemistry for the purposes of modifying saccharide rings, as many five- and six-membered sugars have vicinal diols. Historically it ...