The Fischer projection of D-erythrose is shown below.
D-Erythrose and its isomers are listed as P, Q, R, and S in Column-I. Choose the correct relationship of P, Q, R, and S with D-erythrose from Column II.
Column-I
P.
(see structure)
Q.
(see structure)
R.
(see structure)
S.
(see structure)
Column-II
1.
Diastereomer
2.
Identical
3.
Enantiomer
PQRS
(A)P→2,Q→3,R→2,S→2
(B)P→3,Q→1,R→1,S→2
(C)P→2,Q→1,R→1,S→3✓ Correct
(D)P→2,Q→3,R→3,S→1
Answer: (C)
Solution
Analyzing each structure relative to D-erythrose:
P: Rotating the Fischer projection shows it is identical to D-erythrose → Identical (2)
Q: Has different configuration at one chiral center compared to D-erythrose → Diastereomer (1)
R: Has different configuration at one chiral center compared to D-erythrose → Diastereomer (1)
S: Has opposite configuration at both chiral centers compared to D-erythrose → Enantiomer (3)
Therefore, P→2, Q→1, R→1, S→3.
JEE Advanced · 2020 · 27 Sep 2020 · Paper 1 · Single correct option
