All Questions
Tagged with carbocation reaction-mechanism
56
questions
-3
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0
answers
23
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Stereochemistry of Rearrangements of carbocations [closed]
Suppose in a carbocation ,rearrangement of methyl has to to place to a chiral carbon, forming a stabler cation in the process.But what will be the stereochemistry of the rxn? Will the chiral carbon on ...
2
votes
0
answers
37
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Relation between formation of carbocation and availability of nucleophile
Many sources suggest that in SN1 reactions the leaving group first exits the molecule, and the resulting carbocation is subsequently attacked by the nucleophile, suggesting that there is no relation ...
- 161
1
vote
1
answer
83
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Rearrangment during dehydration of 2,2,5-trimethylcyclopentanol
Here I thought doing the following mechanisms
I thought the product option through the first pathway (left) would be the major product because the intermediate cation is more stabilised due to more ...
2
votes
0
answers
186
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How ring expansion is possible here?
Recently I have came across this question.
I went with the 3rd option as ring expansion cannot occur due to the formed stable 3 degree carbocation. But the answer key claims 4th option. How can ...
- 105
0
votes
1
answer
51
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What nucleophilic reaction takes place in case of bad leaving group as well as 1* alpha carbon?
If we add HI to a substrate Ph-C-C-OH what will be the major product and what reaction mechn. will be followed?
My attempt: as -OH is bad Leaving Group, we cannot just simply proceed with Sn2 and ...
- 23
2
votes
1
answer
163
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Confusion in carbocation rearrangement
In the above dehydration reaction (asked in a competitive examination) I have shown two paths, obviously only one of them is correct.
According to test correct answer is product formed through A but I ...
- 187
3
votes
4
answers
3k
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Hydride shift or Methyl shift
For the carbocation (A) given in the reaction, first we can rearrange it by ring expansion (4 to 5) then we have two choices either H-shift or methyl-shift. My teacher told me that Hydrogen is the ...
- 187
1
vote
0
answers
101
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Why doesn't the protonated propyne rearrange? [closed]
In the reaction of propyne with $\ce{HBr}$ this cation (prop-1-en-2-ylium) was mentioned by my teacher:
$$\ce{H3C-\overset{+}{C}=CH2}$$
He told me that the carbocation will not rearrange as it will ...
- 201
-4
votes
1
answer
103
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Does rearrangement occur in schmidt reaction? [closed]
I recently read about schmidt reaction in which a carboxylic acid is converted to an amine. While forming this, acyl carbocation $(\ce{RCO+})$ is formed, so does rearrangement takes place or reaction ...
- 3
2
votes
1
answer
137
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Decide major product for first order elimination reaction
This is my own created question.
The favourable thing for (c) to be a major product is conjugation of double bonds and highly acidic nature of hydrogen (resulting in elimination of hydrogen at a ...
- 802
3
votes
1
answer
479
views
Second-step activation energy in SN1 reactions
In SN1 reactions, it's known that there are generally two steps, with the first being the R.D.S step involving carbocation formation and the next having a lower activation energy.
Why does the second ...
- 1,134
6
votes
1
answer
720
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Formation of tetrazoles from ketones in Schmidt reaction
Normally in Schmidt reaction of ketones, amides are formed however for some reason here further reaction takes place and a tetrazole is formed. Here is my try for this reaction mechanism (if my ...
- 1,524
2
votes
1
answer
492
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Acids used in Friedel-Crafts alkylation
I am learning adding alkyl groups to benzene using Fridel-Crafts alkylation:
I know that it is very common to use $\ce{AlCl3/AlBr3}$ as Lewis acid catalyst in this reaction. But I am just wondering ...
- 549
10
votes
1
answer
2k
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Why do electron-rich aryl groups have greater migratory aptitudes?
In the following reaction there are three possible aryl groups that can migrate: an unsubstituted phenyl group, a p-methoxyphenyl group, and a p-nitrophenyl group:
Why does the electron-rich p-...
- 169
2
votes
1
answer
303
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Why does ring contraction take place in Wagner–Meerwein rearrangement?
An example of Wagner–Meerwein rearrangement given in my textbook is substitution by $\ce{AgNO2}$ in iodocyclohexane. One of the product, cyclopentylnitromethane is through ring contraction.
I don't ...
- 421