Hydroboration Reaction Lab Report
The Hydroboration Reaction, also known as the Hydroboration-Oxidation Reaction, involves two reactions that are then used to create a final alcohol product. In this reaction, there are a couple of rules that must be remembered:
1. When adding the borane (BH3/THF) through an addition reaction, the BH¬2 will attach to the least substituted carbon atom. This often known as being an anti-Markovnikov formation.
2. Because the reaction occurs all at once (concerted), the H and BH2 will be added to the same side of the molecule. This is known as syn addition.
3. In the last step of the reaction, hydrogen peroxide with a hydroxyl group is then added to replace the BH¬2¬ with OH. This substitution doesn’t change the stereochemistry, as the OH ends
up in the same side (cis) with the H.
This differs from the Oxymercuration reaction slightly. Oxymercuration is another method that is also used to create an alcohol product, but rather than being anti-Markovnikov, this reaction is Markovnikov: the OH group in the end step will be added to the more substituted carbon atom.
1. When adding the borane (BH3/THF) through an addition reaction, the BH¬2 will attach to the least substituted carbon atom. This often known as being an anti-Markovnikov formation.
2. Because the reaction occurs all at once (concerted), the H and BH2 will be added to the same side of the molecule. This is known as syn addition.
3. In the last step of the reaction, hydrogen peroxide with a hydroxyl group is then added to replace the BH¬2¬ with OH. This substitution doesn’t change the stereochemistry, as the OH ends
up in the same side (cis) with the H.
This differs from the Oxymercuration reaction slightly. Oxymercuration is another method that is also used to create an alcohol product, but rather than being anti-Markovnikov, this reaction is Markovnikov: the OH group in the end step will be added to the more substituted carbon atom.