alkenes Flashcards
How can alkenes be prepared?
-dehydration of alcohols using aluminium oxide, concentrated sulfuric acid or concentrated phosphoric acid
-base-induced elimination of hydrogen halides from monohaloalkanes
What reactions can alkenes take part in?
electrophilic addition reactions with:
-hydrogen to form alkanes in the presence of a catalyst
-halogens to form dihaloalkanes
-hydrogen halides to form monohaloalkanes
-water using an acid catalyst to form alcohols
What does markovnikov’s rule state?
when a hydrogen halide or water is added to an unsymmetrical alkene, the hydrogen atom becomes attached to the carbon with the most hydrogen atoms attached to it already.
Markovnikov’s rule can be used to predict major and minor products formed during the reaction of a hydrogen halide or water with alkenes.
How can the products made from the addition of a hydrogen halide and the acid-catalysed addition of water be explained?
the inductive stabilisation of intermediate carbocations formed
