Iodine-based reagents such as
periodic acid (HIO4) and
(diacetoxyiodo)benzene (PhI(OAc)2) are commonly used. Another reagent is
lead tetraacetate (Pb(OAc)4). These I- and Pb-based methods are called the
Malaprade reaction and
Criegee oxidation, respectively. The former is favored for aqueous solutions, the latter for nonaqueous solutions. Cyclic
intermediate are invariably invoked. The ring then fragments, with cleavage of the carbon–carbon bond and formation of carbonyl groups. : Warm concentrated
potassium permanganate (KMnO4) will react with an alkene to form a glycol. Following this
dihydroxylation, the KMnO4 can then cleave the glycol to give aldehydes or ketones. The aldehydes will react further with (KMnO4), being oxidized to become
carboxylic acids. Controlling the temperature, concentration of the reagent and the
pH of the solution can keep the reaction from continuing past the formation of the glycol. == References ==