R,S Nomenclature

Shown below are several different compounds, each of which contains a single stereocenter. This page is meant to provide practice using the Cahn-Ingold-Prelog (or R,S) nomenclature rules. Each of the molecules on this page can be rotated to assist in making the correct assignments. In addition, the color code button can be used to show the correct priority for each group. In order for this page to be useful, you should determine these priorities on your own first, and use the color code button to check your work.

Colors of atoms in 3D Pictures
C H N O F Br
2D Picture Molecules

Hint: to see priorities, press
Color Code
1, 2, 3, 4
Chiral center

To look at a different molecule, select one of the buttons on the right-hand side of the screen. Once you have determined what the correct configuration is (R or S), select the name of the compounds. A new window should appear, giving the correct answer.

Answers