All Questions
Tagged with stereochemistry stereoselectivity
13
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2
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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 ...
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(How) can a reaction be both stereoselective and stereospecific?
From what I have learnt, stereospecific and stereoselective reactions are defined as follows -
Stereospecific - The stereochemistry of the reactant dictates the stereochemistry of the product. Thus, ...
- 1,817
5
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1
answer
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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-...
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1
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How do electrostatic effects effect facial selectivity in addition to cyclic oxo-carbeniums?
I was reviewing Dave Evans' notes for stereochemistry of C=X electrophile additions, and found this slide detailing differences in additions to cyclic oxo-carbenium electrophiles, but I don't ...
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4
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Does syn-dihydroxylation form racemic mixture?
I have been asked to determine the nature of the product for the following reaction:
And as I recognized this reaction to be a case of syn-dihydroxylation, my obvious response was that the product ...
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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 ...
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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 ...
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12
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4
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How is exact racemization possible? [closed]
A racemate consists of 50 % $d$ and 50 % $l$ forms of an optically active compound. But how can someone ensure exact 50% quantity comparing molecule by molecule? There will always be some difference ...
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1
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A question about geometry of benzenetetrol
In the 3d conformation of 1,2,4,5 - benzenetetrol, how could i determine the direction to which hydrogen atoms of hydroxyl groups would point? and if there were tertiary butyl groups in positions 3 &...
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6
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1
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Why does only the cis-isomer of potassium dioxalatodiaquochromate(III) form?
A friend of mine performed a standard synthesis reaction of potassium dioxalatodiaquochromate(III) by adding potassium dichromate to ethandioic acid dihydrate and a little water. The synthesis ...
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Enantioselective alkylation of Aldehydes by Dialkylzinc reagents
Enantioselective catalysis is one of the important reactions in Organic chemistry which has huge applications in practical basis for synthesis of optically pure natural compounds. In this respect, I ...
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3
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answer
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Stereoselectivity of Roush crotylboration
One can use a tartrate derived boronate to enact enantioselective crotyl transfer. Eg in scheme below:
I do not understand how the stereoselectivity arises. We have a chiral boronate, true, and we ...
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6
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1
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Can a stereospecific / stereoselective reaction produce a racemic mixture of enantiomers?
I think I have my terms mixed up but I'm confused about the concept of stereoselectivity / stereospecificity as they relate to reactions with alkenes.
For example, hydroboration is a stereospecific ...
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