Question

Determine R and S for centres 1 and 2

• A. 1-R, 2-S
• B. 2-S, 1-S
• C. 1-R, 2-R
• D. 1-S, 2-R

Answer 1

The correct option is C 1-R, 2-R

Fortunately we have been given Fischer projection directly here.
When we have a Fischer projection,
(i) If least priority group is in the vertical line
$\to$ directly number and give name.
(ii) If least priority group is in the horizontal line,
$\to$ number, name and then interchange the name.
i.e., R becomes S and S becomes R.
So,