A disaccharide X does NOT show mutarotation in aqueous solution. Acidic hydrolysis of X affords two different monosaccharides. The disaccharide X is:
A disaccharide X does NOT show mutarotation in aqueous solution. Acidic hydrolysis of X affords two different monosaccharides. The disaccharide X is:
Show Hint
The Correct Option is D
Solution and Explanation
The key to solving this question lies in understanding the structural features responsible for mutarotation.
- Mutarotation occurs due to the interconversion between \( \alpha \)- and \( \beta \)-anomers of a sugar, which requires a free anomeric carbon.
- If the anomeric carbon of both monosaccharide units in a disaccharide is involved in the glycosidic linkage, then the sugar does not show mutarotation.
- Among the options, structure (D) is sucrose, a disaccharide of glucose and fructose joined by a 1,2-glycosidic bond between both anomeric carbons.
In sucrose:
- The \( \alpha \)-anomeric carbon of glucose and the \( \beta \)-anomeric carbon of fructose are involved in the linkage.
- Therefore, no free anomeric carbon is available, and mutarotation is not possible.
- Hydrolysis of sucrose gives two different monosaccharides: glucose and fructose.
\[ \boxed{\text{Disaccharide X is sucrose (Option D), which does not show mutarotation.}} \]
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