7-2 Naming Alkenes and Alkynes Naming Alkenes Similar to the naming rules for alkanes Step 1-Name the parent hydrocarbon Find longest carbon chain containing the double bond CH3CH2 H CH3CH2 C=C C=C CH3CH2CH2 H CH3CH2CH2 H Named as a pentene NOT as a hexene,since the double bond is not contained in the six-carbon chain OCgLai eat Step 2-Number the carbon atoms in the chain Double-bond carbons should receive lowest possible numbers Begin at end nearer first branch point if double bond is equidistant from the two ends CH3 CH3CH2CH2CH=CHCH3 CH3CHCH=CHCH2CH3 654321 1234567-2 Naming Alkenes and Alkynes ▪ Naming Alkenes ▪ Similar to the naming rules for alkanes ▪ Step 1 - Name the parent hydrocarbon ▪ Find longest carbon chain containing the double bond ▪ Step 2 – Number the carbon atoms in the chain ▪ Double-bond carbons should receive lowest possible numbers ▪ Begin at end nearer first branch point if double bond is equidistant from the two ends