In an IUPAC name a
func. group with higher priority gets the suffix and the lower
priority the prefix. Alkenes and alkynes are infixes.
Functional grp Suffix Prefix Infix
-CO2H -oic acid - -
-CHO -al oxo- -
R2C=O -one oxo- -
-OH -ol hydroxy- -
-NH2 -amine amino- -
-SH -thiol mercapto- -
-C=C -ene - -en-
-X - halo -