JEE Advance - Chemistry (2009 - Paper 2 Offline - No. 9)
The correct statement(s) about the following sugar X and Y is(are)
X is a reducing sugar and Y is a non-reducing sugar.
X is a non-reducing sugar and Y is a reducing sugar.
The glucosidic linkages in X and Y are $$\alpha$$ and $$\beta$$, respectively.
The glucosidic linkages in X and Y are $$\beta$$ and $$\alpha$$, respectively.
Explanation
Reducing sugars contain cyclic hemiacetal or hemiketal groups in equilibrium with the open chain from having a free $$-$$CHO or $$-$$C = O group. Non-reducing sugars contain stable acetal or ketal structures their cyclic structures cannot be opened into an open chain form having a free carbonyl group. In X the glyco-sidic linkage is in between two anomeric carbon atoms while in Y it is only with one anomeric carbon, the other one is free. So, X is non-reducing while Y is reducing.
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