Cycloalkanes = Six carbons = Hexane = Cyclohexane CH 4-2: Nomenclature of cycloalkanes Cycloalkanes The ring is the Parent Chain - count carbons in ring: CYCLOalkane = Six carbons = Hexane = Cyclohexane

Nomenclature: The “Parent Chain” is the ring Nomenclature: The “Parent Chain” is the ring! Count the number of carbons in the ring (alkane) and add the “cyclo” prefix (cycloalkane); number substituents alphabetically; use lowest numbering arrangement. 1-chloro-3-ethylcyclohexane (NOT: 1-chloro-5-ethyl cyclohexane) 1-tert-butyl-2,4-dimethylcyclopentane

Nomenclature: cyclic hydrocarbons may also be substituents: “cycloalkyl” 3-cyclopropyl-4-ethyl hexane