explain the various methods of preparation of alkenes with equation.
Answers
Alkenes belong to the family of hydrocarbons. They contain a double bond between the carbon atoms. The general formula for alkenes is CnH2n. Alkenes preparation can be done by various methods. Explore different methods of preparation of alkenes.
From alkynes: Alkynes are used for the preparation. Alkyne to alkene conversion is carried out by the reduction of alkynes with hydrogen in the presence palladised charcoal. The charcoal used is moderately deactivated with the help of quinoline or sulphur compounds. This reaction results in the formation of alkenes. Palladised charcoal which is halfway deactivated is called as Lindlar’s catalyst. The alkenes obtained from the above reaction have cis geometry. In order to form trans alkenes, alkynes are made to undergo reduction with sodium in liquid ammonia.