All Questions
Tagged with carbocation alcohols
14
questions
1
vote
1
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165
views
What is the rate of hydration in the following compounds
I came across a question :
What is the order of rate of hydration in the following compounds:
My attempt to this question was checking the stability of carbocation. As III has a possibility of 3* ...
- 23
2
votes
0
answers
38
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Which 1,2-methylene shift is more favourable in ring expansions where ring has substituents
In the above reaction, first the -OH group is protonated after which it leaves creating a carbocation intermediate as shown
Now, ring expansion is a more favourable rearrangement, however there is a ...
- 169
8
votes
2
answers
2k
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False positive in lucas test for primary alcohol due to formation of tertiary carbocation by rearrangement?
From Wikipedia:
The Lucas test in alcohols is a test to differentiate between primary, secondary, and tertiary alcohols. It is based on the differences in reactivity of the three classes of alcohols ...
- 193
1
vote
1
answer
717
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Does 2,2-dimethylpropan-1-ol give a positive Lucas test? [duplicate]
I learnt that the Lucas test involves the formation of a carbocation and it gives a positive test based on the stability of the carbocation formed, and hence primary alcohols do not show turbidity (...
- 159
4
votes
2
answers
330
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Mechanism of ring formation of an epoxide under acidic aqueous conditions
I am trying to figure out the mechanism of this reaction:
I think the $\ce{H+}$ will first attack the oxygen of the epoxide and another $\ce{OH-}$ will be added to the most substituted carbocation, ...
- 103
3
votes
0
answers
296
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Major product of isomerization reaction
I am trying to come up with a logical mechanism for the following transformation, where 2-methylenecyclobutan-1-ol is converted to cyclopentanone under acidic conditions:
What I have tried to do was ...
- 3,206
3
votes
1
answer
211
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How is more than one pinacolone is possible?
This question came in one of my school tests. They had given us an unsymmetrical pinacol i.e 1,1-diphenyl-2-methylpropane-1,2-diol and asked us whether it will give only one pinacolone or not.
...
- 159
11
votes
2
answers
2k
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Can a six member ring expand to achieve octet completion to stabilize a carbocation?
(Probably unnecessary background: I came up with this carbocation while predicting the major product of $\ce{NaNO2/HCl}$ with 1-(methylamine)cyclohexan-1-ol)
Will the following carbocation ...
- 9,881
5
votes
1
answer
994
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Are allylic tertiary alcohols oxidized by the Jones' reagent via a classical carbocation intermediate?
I know the mechanism for Jones' oxidation is (picture from Organic Chemistry by Clayden):
and it proceeds through a chromate ester. And in general we understand that the Jones' reagent $\ce{H2CrO4}$ ...
- 9,881
0
votes
2
answers
2k
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Esterification with tertiary alcohol
I saw a different mechanism for esterification of tertiary alcohol in a book.
They say that first the $\ce{OH}$ is protonated and it leaves to form the tertiary carbocation. Then the oxygen's lone ...
- 11
8
votes
1
answer
2k
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Treatment of allylic alcohol with thionyl chloride: why is the product rearranged?
I have read that $\mathrm{S_Ni}$ reactions involving the attack of $\ce{SOCl2}$ on alcohols proceed without the formation of discrete carbocations, and hence there is no rearrangement involved. But ...
6
votes
1
answer
659
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What stops intermediates of alcohol hydration and dehydration reacting in the same way?
I am aware they both occur under different conditions and that water attaches in a secondary position in elimination but primary position in hydration.
(Stage 2)
(Stage 3)
But both appear to be ...
8
votes
1
answer
26k
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Comparison of rate of dehydration of primary, secondary & tertiary alcohols on cyclohexane
Rate of dehydration when given compounds are treated with conc. $\ce{H2SO4}$ is
According to me the answer should be $R > Q > S > P$ but my textbook solution gives the answer as R > Q > P > ...
- 2,106
22
votes
3
answers
51k
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Migratory aptitude in pinacol-pinacolone rearrangement
I am confused about the migratory aptitude of various groups, as there are many different orders for the same given in different places, especially about -Ph and -H. I would like to know if someone ...
- 3,884