Sugar which does not give reddish brown precipitate with Fehling's reagent is:

Step 1: Reducing vs Non-reducing Sugars — Reducing sugars have a free or potentially free hemiacetal or hemiketal group that can open to form an aldehyde or ketone.

Step 2: Sucrose Structure — In sucrose, both the anomeric carbon of glucose ($\alpha\text{-C1}$) and fructose ($\beta\text{-C2}$) are used to form the glycosidic bond.

Step 3: Test Result — Since no free anomeric group is available, sucrose is a non-reducing sugar and does not react with $\text{Fehling's}$ or $\text{Tollen's}$ reagents.

Key Point: Sucrose is the only common disaccharide that is non-reducing.