Question

Rank the following substituents from lowest to highest priority according to the Cahn-Ingold-Prelog rules. = O -CHI3 -OH -NH2 OD, A, E, B OB, E, D, A A, D, E,B E, B, A, D

I’m a bit confused on this topic and how to go about this. Any help or guidance would be appreciated. Thank you!!

Answer 1

Cahn – Ingold – Prelog system priority rules

1) Assign priorities as to the atoms or groups bonded to the carbon atom depending on the atomic number of atom connected to carbon , higher atomic number gets lower number) (more priority).

2) If the first atom attached is same then proceed in the chain till the point of difference is founded.

3) In case of isotopes, higher priority to higher mass number.

4) A multiple bond is considered as both atoms being bonded multiple times

the order of priority according to Cahn – Ingold – Prelog system priority rules is B,E,D ,A

i.e -CHI3 < -NH2 < -OH < =O