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The conversation : CH(3)-underset(OH)u...

The conversation :
`CH_(3)-underset(OH)underset(|)overset(CH_(3))overset(|)(C)-underset(OH)underset(|)overset(CH_(3))overset(|)(C)-CH_(3)underset(H_(2)SO_(4))overset("dil")rarrCH_(3)-underset(CH_(3))underset(|)overset(CH_(3))overset(|)(C)-underset(O)underset(||)(C)-CH_(3)`
is called :

A

Beckmann rearrangement.

B

Pinacol-Pinacolone rearrangement

C

Claisen rearrangement

D

Fries rerragement.

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question regarding the conversion of a diol to a ketone, we will break down the process step by step: ### Step-by-Step Solution: 1. **Identify the Reactants**: The starting material is a diol, which contains two hydroxyl (–OH) groups attached to a carbon chain. The structure shows two carbon atoms each bonded to a hydroxyl group and methyl groups. 2. **Protonation of Alcohol**: When the diol is treated with dilute sulfuric acid (H₂SO₄), the hydroxyl groups get protonated. This means that the lone pair of electrons on the oxygen atom of the –OH group will bond with a proton (H⁺) from the acid, forming a protonated alcohol (oxonium ion). 3. **Formation of Carbocation**: The protonation of the alcohol makes it a better leaving group. The –OH₂ group (water) can leave, resulting in the formation of a carbocation. This step involves the loss of a water molecule, leading to a positively charged carbon atom. 4. **Carbocation Rearrangement**: The formed carbocation can undergo rearrangement to become more stable. In this case, a methyl shift occurs, where a methyl group from an adjacent carbon moves to the carbocation center, stabilizing the positive charge. 5. **Deprotonation**: After the rearrangement, a hydrogen atom from the carbocation is lost as a proton (H⁺), which leads to the formation of a ketone. The resulting structure has a carbonyl group (C=O) and is now a ketone. 6. **Conclusion**: The overall transformation from a diol to a ketone through these steps is known as the **Pinacol-Pinacolone rearrangement**. ### Final Answer: The conversion is called the **Pinacol-Pinacolone rearrangement**.
To solve the question regarding the conversion of a diol to a ketone, we will break down the process step by step: ### Step-by-Step Solution: 1. **Identify the Reactants**: The starting material is a diol, which contains two hydroxyl (–OH) groups attached to a carbon chain. The structure shows two carbon atoms each bonded to a hydroxyl group and methyl groups. 2. **Protonation of Alcohol**: When the diol is treated with dilute sulfuric acid (H₂SO₄), the hydroxyl groups get protonated. This means that the lone pair of electrons on the oxygen atom of the –OH group will bond with a proton (H⁺) from the acid, forming a protonated alcohol (oxonium ion). ...
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When pinacol is treated with dilute H_(2)SO_(4) , a re-arangement reaction takes place which leads to the formation of a ketone. CH_(3)-underset(CH_(3))underset(|)overset(OH)overset(|)C-underset(CH_(3))underset(|)overset(OH)C-CH_(3)overset(H_(2)SO_(4))rarrCH_(3)-underset(CH_(3))underset(|)overset(O)overset(||)C-overset(CH_(3))overset(|)C-CH_(5) This reaction involves re-arrangement of carbocation Step 1: CH_(3)-underset(CH_(3))underset(|)overset(OH)overset(|)C-underset(CH_(3))overset(+)overset(OH_(2))overset(|)C-CH_(2)rarrCH_(3)-underset(CH_(3))underset(|)overset(OH)overset(|)C-underset(CH_(3))underset(|)overset(OH)overset(|)C-underset(CH_(3))underset(|)overset(+)C-CH_(3) Step 2: Carbocation rearrange by hydride, alkyl shift to get as stable as they can. Stability is the driving force for re-arrangement migration of bond may also oC Cur. Where by ring expansion and ring contraction takes place. The relief of strain can provide a powerful driving force for re-arrangement. What will be the product of following reaction R is:

When pinacol is treated with dilute H_(2)SO_(4) , a re-arangement reaction takes place which leads to the formation of a ketone. CH_(3)-underset(CH_(3))underset(|)overset(OH)overset(|)C-underset(CH_(3))underset(|)overset(OH)C-CH_(3)overset(H_(2)SO_(4))rarrCH_(3)-underset(CH_(3))underset(|)overset(O)overset(||)C-overset(CH_(3))overset(|)C-CH_(5) This reaction involves re-arrangement of carbocation Step 1: CH_(3)-underset(CH_(3))underset(|)overset(OH)overset(|)C-underset(CH_(3))overset(+)overset(OH_(2))overset(|)C-CH_(2)rarrCH_(3)-underset(CH_(3))underset(|)overset(OH)overset(|)C-underset(CH_(3))underset(|)overset(OH)overset(|)C-underset(CH_(3))underset(|)overset(+)C-CH_(3) Step 2: Carbocation rearrange by hydride, alkyl shift to get as stable as they can. Stability is the driving force for re-arrangement migration of bond may also oC Cur. Where by ring expansion and ring contraction takes place. The relief of strain can provide a powerful driving force for re-arrangement. What will be the product of following reaction

The monomer of the polymer ~CH_(2)-underset(CH_(3))underset(|)overset(CH_(3))overset(|)(C)-CH_(2)-overset(CH_(3))overset(|)underset(CH_(3))underset(|)(C)~

The IUPAC name of the compound CH_(3)underset(OH)underset(|)(CH)CH_(2)-underset(OH)underset(|)overset(CH_(3))overset(|4)(C)-CH_(3) is

The IUPAC name of the compound CH_(3)underset(OH)underset(|)(CH)CH_(2)-underset(OH)underset(|)overset(CH_(3))overset(|4)(C)-CH_(3) is

When pinacol is treated with dilute H_(2)SO_(4) , a re-arangement reaction takes place which leads to the formation of a ketone. CH_(3)-underset(CH_(3))underset(|)overset(OH)overset(|)C-underset(CH_(3))underset(|)overset(OH)C-CH_(3)overset(H_(2)SO_(4))rarrCH_(3)-underset(CH_(3))underset(|)overset(O)overset(||)C-overset(CH_(3))overset(|)C-CH_(5) This reaction involves re-arrangement of carbocation Step 1: CH_(3)-underset(CH_(3))underset(|)overset(OH)overset(|)C-underset(CH_(3))overset(+)overset(OH_(2))overset(|)C-CH_(2)rarrCH_(3)-underset(CH_(3))underset(|)overset(OH)overset(|)C-underset(CH_(3))underset(|)overset(OH)overset(|)C-underset(CH_(3))underset(|)overset(+)C-CH_(3) Step 2: Carbocation rearrange by hydride, alkyl shift to get as stable as they can. Stability is the driving force for re-arrangement migration of bond may also oC Cur. Where by ring expansion and ring contraction takes place. The relief of strain can provide a powerful driving force for re-arrangement. What will be the product of following reaction CH_(3)-underset(H)underset(|)overset(OH)overset(|)C-underset(H)underset(|)overset(OH)overset(|)CH_(3)overset(H_(2)SO_(4))rarrQ Q is:

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