THE PYRANOSE STRUCTURE OF GLUCOSE S. PORTER MILLER1 American University, Cairo,Egypt
THEteacher's problem of imparting ideas t o his students becomes more and more difficult as these ideas become more complex and obtuse. An illustration which depicts one aspect of a problem often does violence t o another. A case a t point is the use of two dimensional drawings t o illustrate three dimensional ohjects. The pyranose structure of glucose as represented by the Hayworth diagram shows the six member ring excellently, the plane of the ring moderately well. Actu-
ally the ring is of the "boat" or "chair" type as present in cyclohexane. A disadvantage of this diagram is that the beginner may visualize three of the attached groups as being inside the ring rather than above or below the plane of the ring (Fig. 1). Another form in which the six member ring may be represented is as a rectangle. Although it also misrepresents the plane of the ring as a flat surface, it does offer the advantage that the carbon atoms may be pictured as staggered and not coming directly under those above, and the groups attached to these carbons may then be shown completely above or below the plane of the ring (Fig. 2). Not being a freehand artist, the author finds that a reasonablv " eood rectanele is a better blackboard representation of the pyranose structure than a poor hexagon.
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Present address: Westminster College, Fulton, Missouri.
JOURNAL OF CHEMICAL EDUCATION
