Uronate-sugar conjugates natural

V. Selective /3-Eliminative Cleavage of Natural Uronate-Sugar Conjugates.. . 238... 

The amount of the aforementioned uronate-sugar conjugates produced yearly in Nature is very large. Like cellulose and starch, they are among the most abundant natural substances produced by living organisms on the Earth. 

It is difficult to test more exactly the stereochemistry of the different types of endocyclic, enolacetal-forming, /8-elimination processes on the natural, macromolecular, uronate-sugar conjugates. Hence, model compounds have been synthesized on which the alkali-catalyzed, /8-elimination processes could be conducted under well controlled conditions. In addition, the exact determination of certain parameters, such as the conformation of the starting materials used for the experiments and of the reaction products, was much easier than for the macromolecular conjugates. 

Carbohydrates containing uronic acid residues occur in Nature in a wide variety of polysaccharides and other, sugar conjugates of animal, plant, and micro-organism origin. 

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