What are the correct structural descriptions for M and N?
Show Hint
Remember a simple visual trick for Haworth projections of D-sugars:
- Down is \(\alpha\) (like 'A' for Alpha points down).
- Up is \(\beta\) (like 'B' for Beta points up).
This mnemonic helps you identify anomers in a fraction of a second.
M is \(\alpha\)-D-(+)-glucopyranose and N is \(\beta\)-D-(\(-\))-fructofuranose
M is \(\beta\)-D-(+)-glucopyranose and N is \(\beta\)-D-(\(-\))-fructofuranose
M is \(\alpha\)-D-(+)-glucopyranose and N is \(\alpha\)-D-(\(-\))-fructofuranose
M is \(\alpha\)-D-(+)-glucofuranose and N is \(\beta\)-D-(\(-\))-fructopyranose
Show Solution
The Correct Option isA
Solution and Explanation
To determine the correct structural descriptions for M and N, we need to analyze the given structures in the image:
The structure labeled M is a six-membered ring with an oxygen atom. This indicates a \(\text{pyranose}\) sugar, which suggests it is a glucopyranose. The orientation of the hydroxyl group on the anomeric carbon is down, which characterizes an \(\alpha\)-anomer. Therefore, M is \(\alpha\)-D-(+)-glucopyranose.
The structure labeled N is a five-membered ring with an oxygen atom, indicating a \(\text{furanose}\) sugar structure. This is typical for fructofuranose configurations. The orientation of the hydroxyl group on the anomeric carbon is downwards, indicating a \(\beta\)-anomer. Therefore, N is \(\beta\)-D-(\(-\))-fructofuranose.
Given these structural analyses, the correct answer is:
M is \(\alpha\)-D-(+)-glucopyranose and N is \(\beta\)-D-(\(-\))-fructofuranose
This option is valid as it correctly describes the specific forms of glucopyranose and fructofuranose present in the given structures.
