Absolute Configuration

[CoffeeintheMorning]

---

Members don't see this ad.

In terms of absolute configurations, why do we invert the designation when the #4/Hydrogen is coming out of the page?

 

[Thoth]

Because hydrogen has the lowest priority, so it prevents you from having to mentally invert the image, which would be somewhat difficult.

 

[pink_pony47]

By convention, the hydrogen is mentally placed behind the chiral carbon. Then, the priorities are set. As a short-cut trick, you can set the priorities with the hydrogen coming out of the page, but know that the absolute configuration is the opposite of what it would be this way.

 

[CoffeeintheMorning]

By convention, the hydrogen is mentally placed behind the chiral carbon. Then, the priorities are set. As a short-cut trick, you can set the priorities with the hydrogen coming out of the page, but know that the absolute configuration is the opposite of what it would be this way.

Thank you!!!