JEE Main · 2019 · 12 Apr 2019 · Shift 1 · Biomolecules

Glucose and Galactose are having identical configuration in all the positions except position.

(A) $C - 4$ ✓ Correct
(B) $C - 3$
(C) $C - 5$
(D) $C - 2$

Answer: (A)

Solution

Glucose and galactose are epimers: their Fischer projections are identical at every chiral centre except one. The

- OH

C-4

points to the right in glucose and to the left in galactose, while

C-2, C-3

and

C-5

are the same in both. The single point of difference is at

C-4

JEE Main · 2019 · 12 Apr 2019 · Shift 1 · Single correct option

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