Questions tagged [elimination]
Questions whose main focus is on E1, E2, E1cb, or any other type of elimination reaction.
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Why does alcoholic KOH prefer elimination whereas aqueous KOH prefers substitution?
What is the basic difference between aqueous and alcoholic $\ce{KOH}$? Why does alcoholic $\ce{KOH}$ prefer elimination whereas aqueous $\ce{KOH}$ prefers substitution?
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Why does treatment of a geminal dihalide with sodium amide lead to an alkyne and not an allene?
I've come across the following problem in Klein's Organic Chemistry, 2nd edition:
However, I'm a little bit confused about why the terminal alkyne is produced. I believe that an allene should be ...
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2
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Rate of dehydration of alcohols having keto group
The following question was asked in IITJEE-Screening 2000,
Which of the following will be most readily dehydrated in acidic conditions?
I thought that the answer would simply be (c), as its ...
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1
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Elimination reaction mechanism decision (order = 1 or 2)
Match the following:
\begin{array}{}
& \textbf{Column I}&&\textbf{Column II} \\
\text{(A)} & \ce{CH3-CHBr-CD3} \text{ on treatment with alc. KOH gives}& \text{(P)}& \text{E1 ...
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Dehydration of primary alcohols without a β-hydrogen
What happens in dehydrations of primary alcohols (in presence of acid catalyst at high temperatures) which don't have a β-hydrogen?
For example, in the case of neopentyl alcohol, will it dehydrate as ...
- 1,021
7
votes
1
answer
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Elimination of bromine with sodium iodide and electrocyclization
I've been trying to solve the following reaction scheme for a while now and I am having trouble especially with the products E and F.
For product D I got the following, but I'm unsure about ...
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Elimination of HCl from isomeric chlorocyclohexadienes
Which of these is most easily dehydrohalogenated?
a. 5-Chlorocyclohexa-1,3-diene (1)
b. 3-Chlorocyclohexa-1,4-diene (2)
c. 1-Chlorocyclohexa-1,4-diene (3)
d. Both 1 and 3
I encountered this question ...
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Can vicinal dihalide produce conjugated alkene in strong base?
In Klein's Organic Chemistry (3rd edition), p. 410, we learn that vicinal dihalide can produce alkyne in strong base. And on Reaxys I see many reactions of this sort. For example:
However, why isn't ...
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0
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E1CB mechanism with replacement of hydrogen step?
In this question by Jay, one of the sub parts of the total question has the following reaction identified as $\ce{E1CB}$ pathway:
$$\ce{Ph-CH2-CH2Br} \text{ on treatment with } \ce{C2H5OD/C2H5O-} \\
\...
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Why do polarizable nucleophiles favor SN2 over E2?
Weakly basic ions and polarizable bases favor $\mathrm{S_{N}2}$ over $\mathrm{E2}$. Why? The argument used that polarizable nucleophiles form bonds earlier, stabilizing the transition state, can be ...
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How to determine if a base is bulky?
I remember my teacher saying that during E2 (elimination bimolecular) reactions of alkanes, if the strong base that is used as a reagent is a bulky one, it has higher probability of giving a Hofmann (...
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1
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Which will be major and minor alkene formed if E1 reaction occurs on 2-chloro-2,4,4-trimethylpentane?
More substituted alkene should be major product while the less substituted as minor product as it is E1 mechanism.
But in my answer sheet it is given reverse, i.e. major as less substituted and minor ...
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Find the major products when these cyclohexenone bromides react with caustic potash in alcoholic medium:
Question:
Also find the order of the rates of the given reactions.
Answer: The answer of this question is given as option 'D' ie. all products are identical, however I am getting the answer as ...
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How to determine if a reaction proceeds via SN1, SN2, E1 or E2 mechanism?
Give the main product and reaction type: SN1, SN2, E1 , E2.
As the 1-bromohexane is primary and the nucleophile a strong unhindered base, the reaction should be a SN2 reaction. However, the solvent $...
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