Glycol cleavage

The glycol cleavage means the reaction of glycols (1,2- diols ), with oxidizing agents to form aldehydes and ketones.

Lead tetraacetate

Im not yet been fully clarified reaction course is probably cleaved ionic from the diol and the lead tetraacetate esters formed. This cis- diols are cleaved faster than trans - diols. This reaction is named after its discoverer Rudolf Criegee (1902-1975) also known as Criegee glycol cleavage.

Periodic acid

In contrast to periodic acid, lead tetraacetate is water soluble and can therefore be used as a reagent for the organic solvent-insoluble saccharides. Application finds in the determination of ring sizes of glycosides. These names reaction is also known by its discoverer, the French analytical chemist Malaprade Léon (1903-1982), as Malaprade reaction, which they first described in 1934.

In the course of Malaprade cleavage arise from primary alcohols unsubstituted each formaldehyde molecules. From secondary alcohol groups are shown after cleavage of formic acid molecules. In the quantitative analysis of polyols acidimetric a titration of the formic acid is often performed after previous Malaprade cleavage.

The Malaprade reaction also works with α - amino alcohols.

Other applications

• For substances that are sensitive to acid, one can perform the glycol cleavage with sodium periodate.
• If the glycol cleavage is carried out in dextrans with sodium periodate, then you get as high molecular weight poly- aldehydes, because the "molecular backbone" of the dextrans is retained. This poly- aldehydes, the amino groups of proteins bind via Schiff bases which may be used as an adjuvant in immunology.
• For samples which are embedded in a polyacrylamide gel, can be for the gel in place of N, N'-methylenebisacrylamide N, N'- diallyltartardiamide use, and dissolve the gel after the separating operation with sodium periodate by glycol cleavage. This facilitates the examination of the samples, if they are stable against of sodium periodate.
• In the analysis of food sugar substitutes also can be identified together with potassium permanganate as a spray reagent for thin layer chromatography.
• The PAS reaction is a commonly used staining method in histology.