All Questions
Tagged with stereochemistry reaction-mechanism
60
questions
2
votes
1
answer
170
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Explain the mechanism of the following reaction, which involves a 1,2-alkyl migration with double inversion of configuration
I came across the following reaction, whose mechanism is said to involve a 1,2-alkyl migration with a double inversion in configuration. The reagents used were nitrous acid (generated in situ) ...
- 371
1
vote
0
answers
45
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When does the Mukaiyama-Addition follow which transition state and how does it affect the stereochemistry?
in the course on enantioselective organocatalysis, we discussed the route to hexoses via organocatalytic aldol addition and subsequent Mukaiyama addition. The use of either TiCl4 or MgBr2 leads to ...
- 21
0
votes
1
answer
104
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Racemization of hydrocarbon in presence of AlCl3
Our textbook mentioned that the compound in the diagram racemizes in presence of $\ce{AlCl3}$, but it didn't explain anything.
Any help regarding the mechanism of the reaction would be appreciated.
2
votes
0
answers
39
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Sn(II) compound stereoselectivity in aldol reactions
In "advanced organic chemistry: part B" fifth edition, page:130, the authors state that chiral proline-like additives to Sn(II) compounds can further increase stereoselectivity of aldol ...
- 565
5
votes
1
answer
168
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stereoselectivity in aldol reactions
in "Advanced Organic Chemistry, part B" fifth edition book, page:103, the authors compare between aldol reactions where 1-substituted nucleophile is used. They stated that when the 1-...
- 565
9
votes
2
answers
2k
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Determining if the product would be cis or trans after an anti elimination on fischer projections
I find these kind of problems really confusing for some reason, but I saw a way on the web and tried doing it that way:
I considered the basic Fischer operations (Vertical: Below the plane of paper, ...
- 1,218
1
vote
0
answers
36
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Hydroboration, steroselectivity and anti-markovnikov product [duplicate]
My first question has to do with the fact that Hydroboration produces an anti-markovnikov product, why?. I don't see how that happens. A wikipedia artical says that B has a partial positive charge ...
- 11
1
vote
1
answer
58
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Stereochemistry + isomer check
We start with compound M:
[Please imagine green bonds as dotted bonds going into the plane]
From compound M, we are told that the 3 membered ring is opened u using sodium azide yielding a mix of ...
- 109
2
votes
0
answers
48
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Solvent shell collapse
In "advanced organic chemistry part A" book page:306&307 , the author uses the term 'solvent shell collapse' when talking about the reason for retention of conformation in tertiary ...
- 565
1
vote
0
answers
95
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Does orientation matters to this extent in reactions?
In the above question I know that the three reactions involved are $\mathrm{S_N2}$ reactions and therefore there shall thrice inversion of the substitute.
So, I got the solution for the MCQ as:
...
- 317
0
votes
2
answers
159
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What is the mechanism of the reaction of ethyl prop-2-ynoate to ethyl (2Z)-2,3-dibromoprop-2-enoate?
It's really weird for the product is 99％ Z-comformation?
Please tell me why?
This reaction can be found in scifinder.
0
votes
0
answers
2k
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method to certify the number of chiral carbons in fischer and haworth projection of glucose
While reading some notes about Glucose and its various projections:
Fischer Projection: 4 chiral centres
Haworth Projection: 5 chiral centres
My doubt is that is there any (specific) method (...
- 136
1
vote
1
answer
292
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Can anyone tell me what reaction is this?
I came across this reaction, but I have no idea what reaction is this. Can anyone please tell me?
What will be the products?
My first guess is that a carbene will be formed which will attack on the ...
- 193
1
vote
0
answers
69
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Diels Alder stereoselectivity
I'm familiar with the endo rule as well as the regioselectivity of the reaction. However, what I fail to understand is the stereoselectivity of the product in relation to the diene. For example, in ...
- 1,033
7
votes
1
answer
2k
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Racemization of ketones in presence of catalytic acid
Question:
Which of the following ketones racemise in aqueous solution containing acidic or basic impurities?
My answer:
A and B should racemise in aqueous solution, for the carbonyl groups in A and B ...
- 3,862