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Lead(IV) acetate or lead tetraacetate is an metalorganic compound with chemical formula Pb(C 2 H 3 O 2) 4. It is a colorless solid that is soluble in nonpolar, organic solvents, indicating that it is not a salt. It is degraded by moisture and is typically stored with additional acetic acid. The compound is used in organic synthesis. [2]
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 ...
This lack of tight radical pairing is also supported by the observation that alkyl radicals generated by Barton conditions can undergo radical cyclization while analogous intermediates generated by lead tetraacetate oxidation do not. [13] In rare cases, it appears that the alkoxyl radical may epimerize before hydrogen atom abstraction. [14]
Tarnished lead (left) and shiny lead (right) Compounds of lead exist with lead in two main oxidation states: +2 and +4. The former is more common. Inorganic lead(IV) compounds are typically strong oxidants or exist only in highly acidic solutions. [1] Red α-PbO and yellow β-PbO The mixed valence oxide Pb 3 O 4 Black PbO 2 which is a strong ...
Lead sesquioxide, Pb 2 O 3, which is a lead (II,IV) oxide as well (lead(II) metaplumbate(IV) [Pb 2+][PbO 2− 3]), reddish yellow Pb 12 O 19 , monoclinic, dark-brown or black crystals The so-called black lead oxide , which is a mixture of PbO and fine-powdered Pb metal and used in the production of lead–acid batteries .
The oxidation of primary alcohols to carboxylic acids normally proceeds via the corresponding aldehyde, which is transformed via an aldehyde hydrate (gem-diol, R-CH(OH) 2) by reaction with water. Thus, the oxidation of a primary alcohol at the aldehyde level without further oxidation to the carboxylic acid is possible by performing the reaction ...
Lead tetraacetate and lead dioxide are used as oxidizing agents in organic chemistry. Lead is frequently used in the polyvinyl chloride coating of electrical cords. [249] [250] It can be used to treat candle wicks to ensure a longer, more even burn. Because of its toxicity, European and North American manufacturers use alternatives such as zinc.
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 ...