Question

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		Column II
P		1	Diastereomer
Q		2	Identical
R		3	Enantiomer
S

• A. $P \rightarrow 2, Q \rightarrow 3, R \rightarrow 2, S \rightarrow 2$
• B. $P \rightarrow 3, Q \rightarrow 1, R \rightarrow 1, S \rightarrow 2$
• C. $P \rightarrow 2, Q \rightarrow 1, R \rightarrow 1, S \rightarrow 3$
• D. $P \rightarrow 2, Q \rightarrow 3, R \rightarrow 3, S \rightarrow 1$

Answer 1

Answer: (C)

The Fischer projections of $P, Q, R$ and $S$ are

$P \rightarrow 2, Q \rightarrow 1, R \rightarrow 1, S \rightarrow 3$