Ketone Nomenclature (Continued) 3-bromocyclohexanone 3 Br For cyclic ketones,the carbonyl carbon is assigned the number 1. Chapter 18 5 Chapter 18 5 Ketone Nomenclature (Continued) ▪ For cyclic ketones, the carbonyl carbon is assigned the number 1. 3-bromocyclohexanone O Br 1 3