I have a Doubt say if I have to compare -CHO ad -Ch2SH , then which will have highest priority .
See the attached image .
I have another logic if we add all the β position atom's atomic no. then for CHO , 2 O and one H = 17
For CH2SH then 1 S and 2 H = 18
Then -CH2SH will have higher priority .
What is the criteria for such problems ?? Do we compare the highest atomic no. atom or we just add ?? or we See in how much case which substituent is winning ??