Question

Choose the correct relationship for $\alpha -D$-glucose $(A)$ and $\beta -D-$ glucose $(B)$.

• A. A and B are crystal modification
• B. A and B are epimers
• C. A is an aldose and B is a ketose
• D. A is a pyranose sugar and B is a furanose sugar

Answer 1

Answer: (B)

$\alpha$-D-glucose and $\beta$-D-glucose are anomers, because they differ in the orientation of the hydroxyl group at only $C_1$. On the other hand, epimers have several chiral carbons (or centres) differing in configuration about any chiral centre, not necessarily at $C_1$. Thus, all anomers are epimers, but all epimers are not anomers.