COOH priority over alcohol group?

[Chem_Mod]

Question: When you assign an R or S configuration to the chiral center in a molecule, doesn't COOH take priority over alcohol?

[Chem_Mod]

Answer: No. Only compare one bond at a time. Consider each atom bonded to the chiral center, not a functional group, and assign a higher priority to the atom with higher atomic number. If priority cannot be determined by the atoms bonded directly to the chiral center, look at the next set of atoms. Double and triple bonds are considered to be the same number of single bonds connected to that atom.