Chemistry · Ch 13 — Hydrocarbons
Alkenes
Alkenes
Alkenes are unsaturated hydrocarbons containing a carbon-carbon double bond, general formula CnH2n. They are also called olefins (Latin, 'oil maker') because the first member, ethene, combines with …
Nomenclature of Alkenes
Alkenes are IUPAC-named by the same rules used for alkanes (Unit 11), replacing the '-ane' ending with '-ene' and giving the double bond the lowest possible locant. Worked examples include propene, 2-butene, 2-methyl-1-propene, 3-methyl-1-butene (misprinted as '3-methyl-1-propane' at one …
| S.No | Structure (condensed) | IUPAC name |
|---|---|---|
| 1 | CH3-CH=CH2 | propene |
| 2 | CH3-CH=CH-CH3 | 2-butene |
| 3 | CH2=C(CH3)-CH3 | 2-methyl-1-propene |
| 4 | CH2=CH-CH(CH3)-CH3 | 3-methyl-1-butene |
Worked out. A two-part exercise: (1) write IUPAC names for four given alkene structures; (2) draw the structures for four named alkenes -- 6-bromo-2,3-dimethyl-2-hexene, 5-bromo-4-chloro-1-heptene, 2,5-dimethyl-4-octene (printed as '2,5 - Methyl - 4 - octene' in the source) and 4-methyl-2-pentene. …