Question

Determine the R or S designation for each molecule. (Image attached below.)

Answer 1

The molecule on the left is S and the molecule on the right is R.

Answer 2

You wanna start off by ordering the ligands to the central atom in the Cahn-ingold-prelog system (by increasing molecular weight).

so the first one:
then rotate it to have the group of least importance at the back and then trace a circle around in the order of the numbers .

You can do the second one.

Ps what @zacharybean94 wrote is incorrect

Answer 3

@aaronq According to my organic chemistry book, instead of having to rearrange the stereogenic center completely you can just find the configuration "as is" and then reverse it to get the absolute configuration. You always have to place the lowest priority group (4) on the dash, which you didn't do, thus your configuration is incorrect.

Answer 4

@zacharybean94 i understand what you're saying, i arranged the molecule so that the H is at the back (not showing). i'm trying to simplify it for this person to understand how to do it. Your method would work but not in this case.

Show me how that molecule is S configuration, because it isn't.