All Questions
Tagged with stereochemistry nomenclature
61
questions
2
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How the tertiary carbons of cyclohexane are assigned the stereo-descriptors (r)?
We assign the stereodescriptors R and S for chiral centres - carbons and other atoms, as per the set of sequence rules (CIP rules).
The pseudochiral centres are given the descriptors (r) & (s) ...
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3
votes
0
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41
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Systematic method to determine D/L notation of substances other than amino acids and glyceraldehyde
The fundamental rules of D/L notation, as I understand it, are as follows;
In D/L notation, a molecule is named by mapping it to glyceraldehyde.
The D/L notation is based on the stereo configuration ...
- 201
3
votes
1
answer
156
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If the substituents are distinguishable, is it possible to prioritize them using the CIP rules?
In the R/S stereochemical nomenclature,
when we try to determine the priority of substituents around a chiral carbon, are there specific examples where the ranking cannot be definie under the CIP ...
- 201
-1
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1
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9,10-dihydro-9,10-ethanoanthracene derivatives. Stereoisomers or different compounds? What are their chemical names?
What is the relationship between these compounds? Are they stereoisomers or some of them are different compounds? Additionally, what would be their names?
(For position 9, with the methyl substituent)
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5
votes
1
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196
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What is the meaning of "proto" in nomenclature?
"Proto" is generally used to describe "first", "foremost" or "earliest form of (something)" indicating something primitive that transforms into something known ...
- 26.3k
3
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0
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122
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Assigning configuration of chiral plane - selecting of the pilot atom
I am little confused about when it comes to assigning configuration of planarly chiral cyclophanes - and I think it comes down to selection of pilot atom.
All sources I have came across say that the ...
- 392
2
votes
1
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278
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Difficulty in E-Z nomenclature and counting number of geometrical isomers
I have found above four molecules as the geometrical isomers just by drawing them and checking if they are superimposable. I'm not sure that these are the only ones.
I have tried using E and Z but ...
- 169
1
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0
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178
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Stereochemistry R,S configuration
I'm trying to find the R/S configuration of this molecule right here:
At first I tried to find the rotation and then reverse it (since H is pointing outwards), I got an S configuration (drawn poorly ...
- 44
1
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1
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79
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Are substituents placed alphabetically in the name of a cycloalkane?
I named this molecule 1,5-diethyl-2-methyl-4-propylcyclohexane. Is this correct? Or should we somehow use the size of the substituents?
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3
votes
1
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Why is 1,3-dimethyl-cyclohexane a meso compound?
So i was trying to find the plane of symmetry in 1,3-dimethyl-cyclohexane in chair conformation, but then i realised the plane is present only at a particular orientation [see figure]. So why do we ...
1
vote
1
answer
235
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Identify E/Z Configuration
[(2E)-4-ethylhept-2-en-3-yl]cyclopropane why it is named E
Where according to cahn ingold prelog rules At left side Methyl is prior
and on the right side the butane should be prior than cyclopropane
0
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60
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Confusion in D/L nomenclature [duplicate]
With regard to carbohydrates, it is known that in a Fischer projection, if the $-OH$ group is on the right side of the lowest priority asymmetrical (chiral) carbon, then we name it as D and if it is ...
- 583
3
votes
3
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823
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Chiral center or not? Similar substituents, but still two possible structures!
As far as I know, the central carbon shouldn't be a chiral center because it has two identical substituents. And yet, these two compounds should be different from each other.. Is it possible to denote ...
- 341
1
vote
0
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80
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Determining priority for a cyclic compound [duplicate]
I have problem in determining the CIP priorities in (S)-ketamine.
What is the order of priorities for esketamine? Does the carbon bonded to the ring with chlorine have higher priority compared to the ...
- 149
4
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1
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Assigning E–Z configuration for alkenes with cyclic substituent groups [duplicate]
I was taught that according to CIP rules, we must check the priority order for the substituents. But how can we do the same for molecules with cyclic groups as substituents?
How do we compare the ...
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