IUPAC Names for Ketones Replace -e with -one.Indicate the position of the carbonyl with a number. Number the chain so that carbonyl carbon has the lowest number. For cyclic ketones the carbonyl carbon is assigned the number 1. Examples CH: Br 4-hydroxy-3-methyl-2-butanone 3-bromocyclohexanone 4-hydroxy-3-methylbutan-2-oneIUPAC Names for Ketones Replace -e with -one. Indicate the position of the carbonyl with a number. Number the chain so that carbonyl carbon has the lowest number. For cyclic ketones the carbonyl carbon is assigned the number 1. O Br CH 3 C O CH CH 3 CH 2OH 3-bromocyclohexanone 4-hydroxy-3-methyl-2-butanone 4-hydroxy-3-methylbutan-2-one Examples