Nomenclature IUPAC nomenclature requires ketones to be named by replacing the -e ending of the alkyl name with -one Alkane-→alkanone Eg CH;O CH CH- -CH2一CH CH-CH-C-CH-CH CH2一CH 1 old IUPAC names in blue: 2-butanone 2.4-dimethyl-3-pentanone 1-phenyl-1-propanone new IUPAC names in green: butan-2-one 2.4-dimethylpentan-3-one 1-phenylpropan-1-one 0 OH CH3一C-CH2一C一CH CH CH 3-methylcyclopentanone 2-cyclohexenone 4-hydroxy-4-methyl-2-pentanone cyclohex-2-en-1-one 4-hydroxy-4-methylpentan-2-one Chl8 Ketones and Aldehydes (landscape) Page3 Ch18 Ketones and Aldehydes (landscape) Page 3 Nomenclature IUPAC nomenclature requires ketones to be named by replacing the -e ending of the alkyl name with -one. Alkane  alkanone E.g