All Questions
Tagged with stereochemistry carbonyl-compounds
14
questions
-2
votes
2
answers
106
views
Racemization at stereogenic centre [closed]
I am getting a bit confused about why the configuration at the optical centre changes from d to l after enolization?
Any stereogenic centre next to a carbonyl group will be destroyed by enolization. ...
- 15
-2
votes
1
answer
339
views
D and L configuration of monosaccharides
I got this question in the last week's test from Organic Chemistry.
I am a bit confused in assigning D and L configuration.
Help me understand the topic of D and L configuration and help with this ...
5
votes
1
answer
1k
views
What is the difference in dehydration of cis- and trans-1,2-cyclohexanedicarboxylic acid in anhydride formation?
Is there some required stereochemistry for anhydride formation? Do both of them form the same product, or does one not even undergo dehydration?
I looked up cyclohexane-1,2-dicarboxylic anhydride's ...
- 517
1
vote
2
answers
165
views
Chirality and number of sterioisomers
I have recently read that the number of sterioisomers in a compound having n chiral centres is $2^n$. (That is, if no meso form is present)
The below question asks for the number of sterioisomers in ...
- 13
0
votes
1
answer
223
views
Which of the following isomers of 2,3‐dihydroxy‐4‐methoxy‐4‐oxobutanoic acid are identical?
Which of the following are identical?
A and B are identical
A and B are diastereomers
A and C are enantiomers
A and B are enantiomers
What I know is that when we rotate a Fisher projection by 180°, ...
- 371
7
votes
1
answer
2k
views
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
7
votes
4
answers
7k
views
Racemic mixture or not?
Will the following reaction give a racemic mixture or not?
According to me, it should give. But my teacher disagrees, but I cannot understand the reasons he gave. Shouldn't there be equal approaches ...
- 1,629
10
votes
1
answer
2k
views
Enolate formation and tosylate displacement in cis/trans decalin
What will happen in the following reactions? This is Problem 3d from Chapter 6 of Zweifel and Nantz's Modern Organic Synthesis.
I thought that after the hydroxyl group is converted into a good ...
- 14.4k
6
votes
1
answer
3k
views
Masamune's rule of diastereoselectivity multiplicity explained
In a reaction between a chiral substrate and chiral reagent, their asymmetric inductions could cooperate (matched pairs) or compete (mismatched pair). According to Masamune, in a matched pair the ...
- 14.4k
3
votes
1
answer
242
views
What is the reason for enantiomerically pure ketone reaction under acidic conditions giving a 1:1 mixture of diastereoisomers?
(b) Treatment of the enantiomerically pure ketone C under acidic conditions leads to a 1:1 mixture of diastereomers
My thinking is that perhaps the explanation has something to do with the carbonyl ...
- 1,799
7
votes
2
answers
576
views
Bromination of Phenylacetone
Looking at the following reaction, I understand how the product forms, however, can somebody help me understand why two products are formed? Would the identical mechanism produce the two products?
...
- 111
14
votes
2
answers
3k
views
How is the Felkin-Anh model of stereoinduction correctly explained with MO theory?
One method to predict stereoinduction in asymmetric reactions is the Felkin-Anh model (derived from the more basic Cram model) that applies to nucleophile attacks on α-chiral aldehydes. In a ...
- 68.4k
-3
votes
1
answer
236
views
6
votes
1
answer
2k
views
Most stable conformation of aldehydes and ketones
Why is the most favorable conformation of ketones and aldehydes the one where the alkyl group is anti to the other alkyl group (or hydrogen atom in an aldehyde) as attached? Why isn't more stable the ...
- 14.4k