Provide the major organic product in the reaction below. H H K H H3C CH3 CH 3 1. BH3/THF 2. NaOH, H2O2, H2O

The correct answer and explanation is:

The reaction involves hydroboration-oxidation of an alkene. Let’s analyze the mechanism and product formation step by step.

Reaction: Hydroboration-Oxidation of an Alkene

Reagents Used:

  1. BH₃/THF (Borane-Tetrahydrofuran Complex) – This step leads to the addition of boron and hydrogen across the double bond.
  2. NaOH, H₂O₂, H₂O (Basic Hydrogen Peroxide Solution) – This step replaces the boron atom with a hydroxyl (-OH) group.

Regioselectivity:

  • Hydroboration follows anti-Markovnikov addition, meaning the -OH group attaches to the less substituted carbon.
  • The reaction proceeds syn addition, meaning both the hydrogen and hydroxyl group add to the same side of the molecule.

Mechanism:

  1. Hydroboration (Step 1)
    • The alkene reacts with BH₃ (borane) in THF.
    • Boron attaches to the less substituted carbon, while hydrogen attaches to the more substituted carbon.
    • This occurs via a concerted syn-addition mechanism.
  2. Oxidation (Step 2)
    • H₂O₂ and NaOH replace the boron with a hydroxyl (-OH) group.
    • The resulting product is an anti-Markovnikov alcohol.

Final Product:

The major organic product is a primary alcohol (1° alcohol) formed via syn addition. The hydroxyl (-OH) group attaches to the least substituted carbon of the alkene.

Conclusion:

Hydroboration-oxidation is a useful reaction in organic synthesis for converting alkenes into alcohols with anti-Markovnikov selectivity. Unlike acid-catalyzed hydration, this method avoids carbocation rearrangements and provides a predictable primary alcohol as the major product.

Now, I’ll generate an image showing the reactant and product.

Here is the reaction diagram illustrating the hydroboration-oxidation of an alkene. The image was generated using DALL·E, OpenAI’s legacy image generation model. It visually represents the transformation of an alkene into an anti-Markovnikov alcohol using BH₃/THF and NaOH, H₂O₂, H₂O. Let me know if you need any modifications or further explanations!

Scroll to Top