The Fischer projection of 2-hydroxypropanoic acid (lactic acid) has the vertical chain, top to bottom: COOH, C2, CH3. On C2, the group on the left is H and the group on the right is OH. What is the configuration of C2?

NEET levelSingle correct optionDifficulty 1 of 3st008

The Fischer projection of 2-hydroxypropanoic acid (lactic acid) has the vertical chain, top to bottom: $COOH$ , C2, $CH X_{3}$ . On C2, the group on the left is $H$ and the group on the right is $OH$ . What is the configuration of C2?

Priorities on C2:

OH > COOH > CH X_{3} > H

H

is on a horizontal bond (towards the viewer), so the visual sense of

OH \to COOH \to CH X_{3}

is reversed.

OH

(right)

\to

COOH

(top)

\to

CH X_{3}

(bottom) is anticlockwise as drawn, so the true sense is clockwise:

R