CHEM 0310 Lecture Notes - Lecture 11: Sigma Bond, Pi Bond, Carbon-13 Nuclear Magnetic Resonance
Document Summary
To name these organic compounds, -ene is used at the end of alkane names. Alkenes that have the same molecular formula but differ in the location of the double bond are constitutional isomers (double bond isomers) Two alkenes of the same molecular formula only differing in their stereochemistry are called geometric or cis-trans isomers; cis = same side of the double bond, trans = opposite sides of the double bond. These are examples of diastereomers: stereoisomers that are no mirror images of each other. The labels cis and trans cannot be applied when there are three or four different substituents attached to the double-bond carbons. An alternative system is called the e,z system the sequence devised for priority in r,s are applied to the two groups. When the two groups of higher priority are on opposite sides, the molecule is e while if the two substituents of higher priority appear on the same side, the molecule is a z isomer.
