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 cleavage reaction was discovered by Malaprade,1,2 who observed that polyols are rapidly oxidized by periodate ion. Criegee3 subsequently found that lead tetraacetate cleaves 1,2-diols, and Fleury and Lange4 reported that the success of Malaprade's reaction depends on the presence of contiguous hydroxyl groups in the compound. For many purposes, these oxidants are interchangeable; however, the fact that periodate functions best in water, and lead tetraacetate in organic solvents, makes glycol-cleavage oxidation possible with all types of carbohydrates and derivatives.5,6 For favorable examples, the behavior of the two reagents toward a given compound is sufficiently different to provide complementary information. Oxidative glycol cleavage is one of the most widely used methods for determining constitution, usually in combination with such physical methods as NMR spectroscopy and mass spectroscopy. In addition, it furnishes a general, degradative method for the preparation of compounds in the aldotriose, aldotetrose, and aldopentose series, and in the synthesis of a wide range of sugars and derivatives, including isotopically labeled compounds. Several reviews of glycol-cleavage oxidations have appeared.5-9. © 2006 Elsevier B.V. All rights reserved.