Question

each molecule below has one chiral carbon. determine the absolute configuration (r/s) for each.

a. r r
b. r s
c. s r
d. s s

Explanation:

Step1: Determine priorities for molecule I

Assign priorities to groups attached to chiral - carbon based on atomic number. F (highest atomic number) > ethyl > methyl > H. When the lowest - priority group (H) is facing away, the direction of the remaining groups is clock - wise, so it is R.

Step2: Determine priorities for molecule II

For molecule II, OH (highest priority due to O) > ethyl > methyl > H. When the lowest - priority group (H) is facing away, the direction of the remaining groups is counter - clockwise, so it is S.

Answer:

B. R, S