The Structure and Properties of D-Glucose

Glucose is by far the most abundant monosaccharide it occurs free in fruits, plants, honey, in the blood of animals, and combined in many glycosides, disaccharides, and polysaccharides. The structure and properties of glucose will be considered in greater detail than those of the other monosaccharides, not only because of its importance, but because much of what can be said about glucose also can be said about the other monosaccharides. 

Glucose is an aldohexose, which means that it is a six-carbon sugar with a terminal aldehyde group, shown by 1  

Two of the key ideas used by Fischer can be illustrated best with aldo-tetroses because they have only two chiral carbons and far fewer possible structures to consider. Writing the four possibilities as the aldehyde rather than hemiacetal structures, we have 4-7. Of these, 4 and 5 constitute a pair of enantiomers, as do 6 and 7. These pairs can be identified by careful oxidation of the terminal groups to give the corresponding tartaric (2,3-dihydroxy- 

As applied to 4, 5, 6, and 7, the Wohl degradation forms enantiomers of glyceraldehyde  

Products 8 and 9 present a new configurational problem, but a less difficult one than before, because the configurations of two of the three chiral 

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