Understanding Stereoisomers
* Stereoisomers are molecules with the same molecular formula and the same connectivity of atoms but differ in their spatial arrangement.
* Cis-trans isomers (also called geometric isomers) are a specific type of stereoisomer where the difference arises from the arrangement of substituents around a double bond.
Trans-2-pentene
* Has a double bond between the second and third carbon atoms.
* The two largest substituents (methyl groups) on the double bond are on opposite sides of the double bond.
The Stereoisomer
The stereoisomer of trans-2-pentene is cis-2-pentene. Here's why:
* Cis-2-pentene also has a double bond between the second and third carbons.
* The key difference: The two methyl groups are on the *same* side of the double bond.
Visual Representation
Here's a simple way to visualize it:
* Trans-2-pentene: CH3-CH=CH-CH2-CH3 (Methyl groups on opposite sides)
* Cis-2-pentene: CH3-CH=CH-CH2-CH3 (Methyl groups on the same side)
