Saccharides carbonyl group, addition

In addition to their aldehyde or ketone form, saccharides can also exist in a cyclic form. Figure 24-10 shows the interconversion of glucose between its linear form and its cyclic form. Figure 2 4-10b shows the molecule rotated into a conformation that brings the hydroxyl group of carbon 5 near the aldehyde carbon. In this conformation, a reversible reaction occurs in which a hydrogen is moved from the hydroxyl group to the carbonyl... 

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