Question

Glucose generally exists in ring (cyclic) form. A Haworth projection shows the orientations of the hydroxyl groups and hydrogen atoms on the ring. Draw the alpha and beta forms of glucose by moving the groups (H, OH, or CH2OH) to the appropriate positions.

Answer 1

Concept and reason

The concept used to solve this question is to draw the $\alpha$ and $\beta$ forms of glucose.

Fundamentals

Haworth projection is the method of representing monosaccharides in a cyclic ring.

Similarly, glucose is a monosaccharide and can be represented as Haworth projection.

Anomers are the two structural forms of same molecule which differentiate from each other only in the direction of the OH (hydroxyl) group present at the hemiacetal carbon (C1). The molecule having $- {\rm{OH}}$ group in the upward direction is called as $\beta$ anomer. The molecule having $- {\rm{OH}}$ group in the downward direction is called as $\alpha$ anomer.

1.

The chair conformation of glucose is as follows:

The $\alpha$ form of glucose is as follows:

2.

The chair conformation of glucose is as follows:

The $\beta$ form of glucose is as follows:

Ans: Part 1

Therefore, the $\alpha$ form of glucose is as follows:

Part 2

Therefore, the $\beta$ form of glucose is as follows: