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In the following reactions CH3-overset(...

In the following reactions `CH_3-overset(CH_3)overset(|)CH-underset(OH)underset(|)CH-CH_3overset(H^+//heat)rarrunderset([underset("product")"Major"])A+underset([underset("product")("Minor")])B`
(ii) `Aoverset("HBr, dark")underset("in absence of peroxide")rarrunderset([underset("product")"Mejor"])C+underset([underset("product")("Minor")])D`
The major products A and C are repectively

A

`CH_2=overset(CH_3)overset(|)C-CH_2-CH_3" and" underset(Br)underset(|)CH_2-overset(CH_3)overset(|)CH-CH_2-CH_3`

B

`CH_3-overset(CH_3)overset(|)C=CH-CH_3 " and "CH_3-overset(CH_3)overset(|)underset(Br)underset(|)C-CH_2-CH_3`

C

`CH_3-overset(CH_3)overset(|)C=CH-CH_3 " and "CH_3-overset(CH_3)overset(|)CH-underset(Br)underset(|)CH-CH_3`

D

`CH_3-overset(CH_3)overset(|)C=CH-CH_3 " and "CH_3-underset(Br)underset(|)overset(CH_3)overset(|)C-CH_2-CH_3`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the given question step by step, we will analyze the reactions and determine the major products A and C. ### Step 1: Identify the starting material The starting material is a compound with the structure: ``` CH3 | CH3-CH-CH2-CH3 | OH ``` This compound is a secondary alcohol. ### Step 2: Perform dehydration reaction When the secondary alcohol is treated with H+ (acid) and heat, dehydration occurs. The hydroxyl group (OH) is protonated to form a better leaving group (H2O). The reaction proceeds as follows: 1. Protonation of the OH group leads to the formation of a good leaving group (H2O). 2. The water molecule leaves, forming a carbocation. ### Step 3: Carbocation formation and rearrangement The initial carbocation formed is a secondary carbocation. However, secondary carbocations can rearrange to form more stable tertiary carbocations through a hydride shift: - The hydrogen from the adjacent carbon shifts to the carbocation center, resulting in a more stable tertiary carbocation. ### Step 4: Formation of alkene (Product A) From the tertiary carbocation, we can eliminate a hydrogen atom to form an alkene. The major product A will be formed by removing a hydrogen from the carbon adjacent to the carbocation: - The major product A is: ``` CH3 | CH3-C=CH-CH3 ``` This is the more stable alkene due to the more substituted double bond. ### Step 5: Identify minor product B The minor product B can be formed by removing a hydrogen from the original carbon that was not involved in the rearrangement. This leads to a less substituted double bond: - The minor product B is: ``` CH2 | CH3-CH=CH-CH3 ``` ### Step 6: Reaction of Product A with HBr Next, we react product A with HBr in the dark (absence of peroxide). According to Markovnikov's rule, the H+ will add to the carbon with more hydrogens (the less substituted carbon), leading to the formation of a more stable carbocation: - The major product C formed will be: ``` CH3 | CH3-C(Br)-CH2-CH3 ``` This is the major product C. ### Step 7: Identify minor product D The minor product D can be formed by the addition of Br- to the less substituted carbon, leading to a less stable product: - The minor product D is: ``` CH3 | CH2-CH(Br)-CH3 ``` ### Conclusion - Major product A: `CH3-CH=CH-CH3` (more substituted alkene) - Major product C: `CH3-CH(Br)-CH2-CH3` (from the addition of HBr)

To solve the given question step by step, we will analyze the reactions and determine the major products A and C. ### Step 1: Identify the starting material The starting material is a compound with the structure: ``` CH3 | CH3-CH-CH2-CH3 ...
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