Reactions of alkenes
* Hydrogenation:
Hydrogenation is the addition of hydrogen to the double bond to form alkanes.
Platinum and palladium are the most commonly used catalysts in the hydrogenation of alkenes.
![2.1- ejemplo 1 reacciones de alquenos[517].jpg](https://images.ecency.com/p/FUkUE5bzkAZVVKmXhtvgKqwbwBkEW2Zw4TQ1mz834y917pHYwd3GnX7gx4cvg9Sd33dshMGYvyYTEF3evmCXEjNmmsjFPtHd2H1fcS1etQ8RehW2HWuGp9otsD1B3VQAE4XCLDmrbKaVNquQHiGCVsJAx9xypdesBCei?format=match&mode=fit)
* Addition of H2O:
The addition of water to a double bond C = C produces an alcohol and is the opposite reaction to the dehydration of the latter. Therefore, it is reversible. Whether it is given in one way or another will depend on the amount of water in between.
These reactions take place through carbocations, with the consequent problem of the possibility of transpositions and the obtaining of unexpected products.
* Halogenation:
When a halogen is reacted with an alkene, an addition reaction is carried out, and a local alkyl dihalide is formed as a product.
![2.2- ejemplo 2 reacciones de alquenos[518].jpg](https://images.ecency.com/p/FUkUE5bzkAZVVKmXhtvgKqwbwBkEW2Zw4TQ1mz839u1XSeSmrRV32qFTBK8BeiuNnYuntwe4CnXggtbGwGdJnqa41a7fRNTPn4T4dX2Ej7zGS6gX1XiUyLwR8QQqnKpnDzWctnXvqoaY4ut1vgHhaEfu5zB2sNYpg7bt?format=match&mode=fit)
* Formation of halohydrins:
The alkenes react with halogens in an aqueous medium to form halohydrins, compounds containing a halogen and a hydroxyl group in neighboring positions.
![2.3- ejemplo 3 reacciones de alquenos[519].jpg](https://images.ecency.com/p/FUkUE5bzkAZVVKmXhtvgKqwbwBkEW2Zw4TQ1mz82xpFwoq9tGehnBxhxnZJDkZQ5a9o4UU4KJ3z2mahC9qmTNmhKhwwDFu2E7KqStJnqVuHvm4d6JxcdXPJdWREzbJmwbAQ3PoNmNREyE2Ao3nD84VudJVFEondqcjnN?format=match&mode=fit)
* Addition of HX (Hydrogen Halogenide):
The hydrogen halides are added to the double bond by a mechanism similar to the addition of bonds. The regioselectivity of the addition to the double bond of H-X also follows the Markovnikov rule.
![2.4- ejemplo 4 reacciones de alquenos[520].jpg](https://images.ecency.com/p/FUkUE5bzkAZVVKmXhtvgKqwbwBkEW2Zw4TQ1mz83AXDAPFim2ZeJbVJvGXuLC8cFpYkSutHi1h3j3MA37TX928CjCso4Eb8pTJfRPcksgDgJacyXa3ceVQ3YLdabuELxF4Q2hhFFzUe6RNereQSNUZnb1rrZCerVVp2J?format=match&mode=fit)
* Dimerization:
The dimerization consists of the union of two molecules of acid through the formation of bonds by hydrogen bridge between the H of the carboxyl group of an acid, with the O of the -C = O of the other acid.
This means that when the dimerization appears, it is observed when studying the properties of the acid, that it actually has twice the molecular mass of the expected one.
![2.5- ejemplo 5 reacciones de alquenos[521].jpg](https://images.ecency.com/p/FUkUE5bzkAZVVKmXhtvgKqwbwBkEW2Zw4TQ1mz834GhijKzHHzc7dJoqYU7zTJR4i3pkXmyPgpmU6BqYw5WqxYvNbCJbszpeqQBwk7AWnwzn9yd724bzSvAN6eNzfsCCF1x6VDT3id3iqAb2cRC9KgTKYhbY6Q35YzkE?format=match&mode=fit)
* Polymerization:
It is the breaking of the double bond to form free radicals and those in turn form bonds with other molecules of the same alkene, until reaching a certain molecular weight. The function of the initiators is to break this double bond through the union with these initiators, once joined, another free radical is sought that joins the first molecule of the alkene.
![2.6- ejemplo 6 reacciones de alquenos[522].jpg](https://images.ecency.com/p/FUkUE5bzkAZVVKmXhtvgKqwbwBkEW2Zw4TQ1mz832zthLLxYkYLKv1q18cBAx44BHk5LAHcmCQPrRJuvsZA2GT8ZpqmPDVy9SXfzz9Af7vG4sSX9aXw7HKgxHteMDiHat7WKdCAWEncwyWGtaadWzd9TGcYtUfSyD5Hx?format=match&mode=fit)
* Ozonolysis:
It is the breakdown of the carbon-carbon double bond of the molecule, oxygen binds to each of the two atoms that form the original double bond forming aldehydes or ketones.
![2.7- ejemplo 7 reacciones de alquenos[523].jpg](https://images.ecency.com/p/FUkUE5bzkAZVVKmXhtvgKqwbwBkEW2Zw4TQ1mz82xoLTrRHP6bc5pXUWD9qCkX5UoH5hNQQubb86ErSSNanhmJ1TfaMpUrWMidYtrgsTx7pZNjzPnao3xVJQpRVjoWvw3HBkuvM34iPTf16LRG3mkcWbHEEoR2cAh7ot?format=match&mode=fit)
For more information, you can visit the following links:
- https://www2.chemistry.msu.edu/faculty/reusch/virttxtjml/addene1.htm
- https://www.aceorganicchem.com/guides/alkene_reactions.pdf
- https://crab.rutgers.edu/~alroche/Ch08.pdf
