Nomenclature of Alkenes Simple alkenes are named like alkanes (root from the longest carbon chain),but the-ane suffix is replaced by-ene. CH,-CH CH,=CH一CH IUPAC names: ethene propene cyclohexene Common names: ethylene propylene 每03 son Eaurtin ire When the chain is longer than 3 carbons,number the atoms such that the double bond is given the lowest number (i.e.start at the end nearest the double bond). CH2=CH-CH,-CH: CH,-CH-CH,-CH,-CH old IUPAC names: 1-butene 1-pentene new IUPAC names: but-l-ene pent-l-ene 3 CH,一CH=CH一CH3CH3一CH=CH一CH2一CH old IUPAC names: 2-butene 2-pentene new IUPAC names: but-2-ene pent-2-ene Ch07 Alkenes:Struct synth (landscape) Page 6Ch07 Alkenes; Struct + synth (landscape) Page 6 Nomenclature of Alkenes Simple alkenes are named like alkanes (root from the longest carbon chain), but the –ane suffix is replaced by-ene. When the chain is longer than 3 carbons, number the atoms such that the double bond is given the lowest number (i.e. start at the end nearest the double bond)