Organic Chemistry III
	Professor Carl C. Wamser
Chem 336 - Spring 2009	Quiz 25

1. (3 points) D-Mannose is the C2-epimer of D-glucose.
Write accurate structures for D-mannose in

a) open-chain form in standard Fischer projection

b) a beta-pyranose form in Haworth projection

c) a beta-pyranose form in its best chair conformation

2. (2 points) Write a structure for the alpha-furanose form of D-ribose-5-phosphate.

3. (2 points) Reduction of D-fructose by NaBH4 gives two epimers. Write both structures in standard Fischer projections.

4. (3 points) Write a complete mechanism that shows the acid-catalyzed conversion of the beta-pyranose form of D-glucose to its alpha-pyranose form.
Show all resonance forms for any intermediates involved.