Orgo R/S stereochem

[nickh]

---

Members don't see this ad.

Hey guys,

So for the question before, I know what's an R and S, and how to assign them. But the part that I'm struggling with is how do you tell if the the H is pointing away or towards you, because that would affect if one would be an R or S. Please share any tips 🙂

Thanks!

 

[DocVaquero]

Similar to the hashed-wedged line structures, horizontal lines are indicative of bonds coming towards the viewer, while vertical lines indicate bonds going away from the viewer.

Hope this helps.

 

[nickh]

oh really? hah, i did not know this at all. yep, that totally helps! thanks so much 🙂

 

[zoey1234]

imagine a bow tie, the hydrogen or any molecules that are located on the "bow tie" = horizontally --> its wedge
if vertically, its dash.

 

[DAT Destroyer]

Hey guys,

So for the question before, I know what's an R and S, and how to assign them. But the part that I'm struggling with is how do you tell if the the H is pointing away or towards you, because that would affect if one would be an R or S. Please share any tips 🙂

Thanks!

Here is a simple way to do this, assign group priorities first according to atomic number. Draw an arrow going from group priority 1 to group priority 2 even if it necessitates going over group number 4 . Now here is the trick, if group number 4 is on the vertical, clockwise is R and counterclockwise is S. If group number 4 is on the horizontal reverse your thoughts. For example if you expect R and number 4 is on the horizontal the configuration will be S.