Organic Chemistry III
	Professor Carl C. Wamser
Chem 336 - Spring Term	Quiz 23

1.  (6 points)  The structure shown below is a pyranose form of D-arabinose.

(1)  Is this alpha or beta at the anomeric carbon? BETA

(2)  Write the other chair form for the same structure above.

(1)  Write the open-chain structure for D-arabinose.

(2)  Write a Haworth structure for alpha-D-arabinofuranose.

2.  (2 points)  Complete the following reactions by using structures of the products (open-chain).

a)  D-glucose  +  NaBH4 -->

b)  O-methyl-D-fructofuranoside  +  HCl (H2O) -->

3.  (2 points)  Write the structure of the disaccharide that would be formed by joining D-glucose from its C-1 alpha to the C-4 of D-ribose.  Write both as pyranose rings in Haworth projections.