Glycol-cleavage oxidation.

Publisher Summary This chapter provides an overview of glycol-cleavage oxidation. Carbohydrates provide a profusion of compounds that contain hydroxyl groups on two or more adjacent carbon atoms, and the fact that this type of carbon–carbon bond generally undergoes oxidative scission selectively and quantitatively has been a major factor contributing to the current status of carbohydrate chemistry. The fact that periodate functions best in water and leads tetra-acetate in organic solvents, makes glycol-cleavage oxidation possible with all types of carbohydrates and derivatives. The high selectivity of periodate and lead tetraacetate as glycol-cleaving oxidants is attributed mainly to the ability of the central atom of the reagent to complex with a 1,2-diol and effect a two-electron transfer. Formation of an intermediate complex has been shown for periodate by pH and ultraviolet spectral changes, and, for both oxidants, less directly by the consideration of the reaction kinetics. The glycol-cleaving action of periodate is generally more consistent with the concept of a five-membered ring intermediate than is the action of lead tetraacetate. The characteristics of periodate and lead tetra-acetate oxidations are explained in the chapter. It also discusses the properties of glycosides and related alicyclic compounds and explains the oxidation patterns and end-group analysis of polysaccharides.