Question

II. NO2 CNLH DOO

my question is how to identify a priority. Is it by atomic mass? How does the methyl group attached to the lowest priority affect both? what would be the numbered priority for both of these ?

for the first picture I know F is the priority and for the second picture I know Br would be the priority number one (for the top chiro center) although I’m not sure which one would be number two since it is attached to another chiral center. or how you would determine that.

Answer 1

The procedure procedure to determine the priority by using on to Prelog Convention for a given store ocenter to of by using Cahne given - Stop - Draw and find the stereo center Step- All gro a priority that step-♡ Identify the and arrange O Draw the structure and find the stored the moleculat structure. 2 All groups affached to the stereocenter are assigned writy that is based on the atomic number. Identify the atoms attached to the stereocenter mange these atoms in order of increasing nomber (2). The afour with highest atomic ave higher priority than the atom with atov I nomber have higher priority lowest atomie number, Stap - Change your view of are & Change your view of the molecole so that you looking along the bond between the stereocenter and lowest priority group, with the lowest priority group facing away from you. Step - Note the direction in which the priorities decrease. when the priorities decrease in a clockwise manner, then the stereocenter has Rutorom (R-rectus, means right), when sterbocenter the priorities decrease in a antic lockwise manner, them the stereocenter has storm (s- Sinister, left).

Cl I In this molecole, there are two stare ocenter (a) and (b). then the priority to the group attached to the each stereocenter are given below- Stereocenter (a) - nf >-No > C-a H Streocenter (6) --Cl >-c-Nog >-CHCH₂ 7-H In this molecole, there are two stercocenter (9) and (b) then the priority to the group attached to the each stereocenter are given below- Stereocenter (9) - Br J NHg STSH) F (NO2) > CH₂ CH₂ Stereocenter (b) - Hs7f7NO2

In the above question priority of the of the group attached to the stereocenter is decided by atomic number not by atomic mass. The procedure for the determination of priority of the groups attached to the stereocenter is given above.