Sugar which does not give reddish brown precipitate with Fehling's reagent is:
- (A)Sucrose✓ Correct
- (B)Lactose
- (C)Glucose
- (D)Maltose
Answer: (A)
Solution
Sucrose has no free anomeric (hemiacetal) carbon — both its anomeric carbons are tied up in the glycosidic bond — so it cannot reduce Fehling's reagent. Glucose, lactose and maltose each retain a free hemiacetal/aldehyde group and give a positive test.
JEE Main · 2024 · 30 Jan 2024 · Shift 1 · Single correct option