Alkenes Flashcards
What are the methods for preparing alkenes?
Dehydration of alcohols using aluminium oxide, concentrated sulfuric acid, or concentrated phosphoric acid.
Base-Induced Elimination: Removal of hydrogen halides from monohaloalkanes.
What reactions do alkenes undergo?
With Hydrogen: Undergo electrophilic addition to form alkanes in the presence of a catalyst.
With Halogens: React to form dihaloalkanes.
With Hydrogen Halides: React to form
monohaloalkanes.
With Water: React using an acid catalyst to form alcohols.
What is Markovnikov’s Rule?
When a hydrogen halide or water is added to an unsymmetrical alkene, the hydrogen atom attaches to the carbon with the most hydrogen atoms already attached to it.
Predicts major and minor products in alkene reactions with hydrogen halides or water.
How are the mechanisms for the addition of hydrogen halide and acid-catalysed addition of water represented?
represented using curly arrows and intermediate carbocation.
The products are explained by inductive stabilisation of intermediate carbocations.
How is the addition of halogen mechanism represented?
Represented using curly arrows and showing the cyclic ion intermediate.
