# Optical isomerism

• Option b is correct

• @Tech-With-Us πππ there are two b options

• I am getting RR

Draw Fischer and check

• This post is deleted!

• @Kirito on what basis the periority order decided

• @Tech-With-Us Step1: Draw an arrow starting from priority one and going to priority two and then to priority 3
Step2: see that If the arrow goes clockwise, the absolute configuration is R. As opposed to this, if the arrow goes counterclockwise then the absolute configuration is S. In this question both the arrow is coming in clockwise direction so the answer is R,R. For getting this you have to make fischer projection of this configuration.
Priority order is decided on these following basis:
(1) Atom of higher atomic number gets priority. Atom of higher priority is assigned no.1 & atom of least priority is further.
(2) If the first atom is the two groups have same atomic number then relative priority of the group is decided by a comparison of the atomic number of the next atom in the two groups.
(3) Multiple bonds are treated as separate single bonds.
For Ex: βCH=O is given priority over βCH2OH
I>Br>Cl>OH>NO2>NH2>COOH>CHO>CH2OH
Fischer projection of the configuration is:

• @Tech-With-Us on the place of @Kirito i am giving this answer....the priority order basically depends on:
(1) Atom of higher atomic number gets priority. Atom of higher priority is assigned no.1 & atom of least priority is assigned further.
(2) If the first atom is the two groups have same atomic number then relative priority of the group is decided by a comparison of the atomic number of the next atom in the two groups.
(3) Multiple bonds are treated as separate single bonds.
For Ex: βCH=O is given priority over βCH2OH
I>Br>Cl>OH>NO2>NH2>COOH>CHO>CH2OH
I have provided the full solution above.