For question relating to isomers which cause plane polarized light to be rotated in opposite directions.

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2answers
73 views

Possible Products in the Addition To a Double Bond in a Ring

I don't understand why both these products should be different. I know hydrogenation is syn addition and both the hydrogens add from the same side, but why should the plane in which both the ...
1
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1answer
31 views

Propene react with ICl

When propene react with ICl , it gives an inoptically active compound ,why. According to me there is chiral carbon so it should be optically active
7
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3answers
318 views

How do atoms with 3 different covalently bonded substituents and one electron pair behave?

If one has a carbon atom with 4 different groups covalently bonded to it, it is called asymmetric and there can be enantiomers etc. But imagine if one has a different central atom, for example a ...
0
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0answers
15 views

Chirality of carbon and R/S naming when enatiomeric groups attached [duplicate]

when checking chirality for a tetrahedral, let's take carbon as an example, will two enantiomers or diastereomes of a group attached to same carbon cause chirality at that carbon, I mean are they ...
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votes
2answers
35 views

Hands and chirality [duplicate]

I was told by my teacher that human hands are the best examples of chirality as both the hands are mirror images of each other but cannot be superimposed on each other. My question is if we join ...
2
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1answer
39 views

Chair conformation chirality

I have two questions regarding this solution: I can't see how the structure drawn is the enantiomer. How do I rotate the ring inversion chair form to obtain the enantiomer?
4
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2answers
60 views

What causes rapid nitrogen inversion?

When I asked my teacher whether a nitrogen bonded to 3 unique groups counted as a chiral center, they said that it did not because nitrogen undergoes rapid inversion at room temperature. What causes ...
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0answers
40 views

How do I assign R/S configuration?

So I have this molecule shown up here and I need to give its systematic name according to the UIPAC and need to give its R/S configuration in the name. I suspect the name to be ...
0
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0answers
44 views

dextroamphetamine - D or L

Is dextroamphetamine D or L? I know it has S configuration, but I keep getting it as D. I know usually D has R configuration, while L has S configuration. But, when I am drawing the molecule, I ...
0
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0answers
31 views

Chiral compound

Among the four compound , there is one compound which is chiral compound . But according to me, all compounds should be chiral as all the compounds contain chiral carbon.
8
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1answer
106 views

How did chemists before 1951 ensure that assigning D, L config. to every chiral molecule would result in same config. as the standard enantiomers?

The D and L (small caps) system I have referred to is the one chemists used before CIP's (R/S) system where they arbitrarily assigned the (+) and (-) isomers of glyceraldehyde, 'D' and 'L' ...
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0answers
46 views

Chiral molecules [closed]

There are three compounds among these first and second are chiral as they have chiral carbon . But why the third compund is not a chiral compound and according to me it has two chiral carbon .
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0answers
23 views

Optically active [closed]

In the following compounds , how can we say that both are are optically active . According to me they both do not have chiral carbon , then how can we say that both are chiral .
2
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3answers
107 views

Is rotation of a mirror image allowed in order to determine chirality? Doesn't rotation alter the mirror image of the molecule?

So, chiral molecules are those which have non-superposable mirror images. trans-1,2-Dimethylcyclopentane is chiral; 2-butanol is chiral; both don't superpose on their mirror image. Then my book ...
4
votes
1answer
251 views

How to determine optical activity of a compound without asymmetric carbons theoretically? [closed]

I know that a compound doesn't need to have a chiral carbon to be optically active. So how can I find out whether a compound drawn on paper is chiral without access to any experiments? e.g. ...
10
votes
1answer
170 views

Taste of sugars' unnatural enantiomers

I'm wondering about how L-sugars taste. They are obviously not digestible by humans, but what do they taste like? If they are sweet, too, why isn't sucrose with the unnatural chirality used as a ...
1
vote
1answer
105 views

(Effective) number of molecules interacting with light to produce optical activity

The question is: How can I get a sensible and concrete (not relative) value for the number of molecules light has interacted with to cause an optical activity phenomenon? Specifically, my issue in ...
1
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1answer
45 views

Separating Enantiomers

I understand that you can react enantiomers with a chiral molecule to resolve the enantiomers of interest into diastereomers. However I do not understand how exactly the added chiral molecule can ...
1
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0answers
41 views

Chirality Centers of Albuterol-like Compounds

My question is apart from the C in the straight chain with $\ce{-OH}$ group, should $\ce{N}$ be counted as chirality center since it also has tetrahedral geometry and all different substituents? ...
2
votes
1answer
164 views

What kind of optical activity requires chirality?

From "Meso compound" in Wikipedia: A meso compound or meso isomer is a non-optically active member of a set of stereoisomers, at least two of which are optically active. This means that ...
3
votes
0answers
66 views

What symmetry elements mustn't a molecule possess to be considered achiral?

Undergraduate textbooks say that a molecule mustn't posses a reflection plane and an inversion center to be considered achiral. As mentioned by Ron in his answer to this question, molecules that don't ...
2
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0answers
35 views

How to interpret the rate constants of in-vivo racemization of thalidomide?

The article by Eriksson et. al. found that thalidomide undergoes chiral inversion in vivo. It found the mean rate constants too, $0.17~\mathrm{h^{-1}}$ (R to S) and $0.12~\mathrm{h^{-1}}$ (S to R). ...
3
votes
1answer
46 views

How can it be proved that (S)-bis-[2-(t-butylsulfinyl)phenyl] diselenide is a chiral non-racemic product?

I read in paper that: The aim of this part of the work was to synthesise new aromatic diselenides with chiral phosphorous or sulfoxide centres in coordinative distance to the selenium as ...
4
votes
2answers
88 views

How to determine the number of stereoisomers of a di-substituted allene, exhibiting both axial and central chirality?

What are the diastereomers and enantiomeric pairs of the compound below where A are chiral groups (central chirality)? There should be 3 diastereomers and 3 enantiomeric pairs (last page). I ...
5
votes
1answer
196 views

How to find the number of stereoisomers of a tetra-substituted allenes, exhibiting both axial and central chirality?

I need a reliable method for determining the number of diastereomers and enantiomeric pairs of the following series of compounds bearing in mind that the substituent groups A are chiral on their own ...
5
votes
2answers
362 views

Axial or planar chirality in spiro[3.3]hepta-1,5-diene

The two spirocyclic compounds drawn below are enantiomers. My question is, do they exhibit axial or planar chirality? 3D representations:
7
votes
2answers
146 views

Do more double bonds cause a bigger number of stereoisomers in cycloalkenes?

If trans double bonds cause cycloalkenes to be chiral, does a second trans or maybe cis double bond induce another chiral plane and hence four stereoisomers are possible for the given cyclodiene? The ...
10
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2answers
420 views

Are all higher cycloalkenes chiral?

Are all higher trans-cycloalkenes chiral as trans-cyclooctene is? This question supplements my previous question: Why is trans-cyclooctene chiral? See also the follow-on question: Do more double ...
8
votes
2answers
432 views

IUPAC name for 1,2,3-trichlorocyclopropane?

What is the IUPAC name for the two isomers of 1,2,3-trichlorocyclopropane? Similarly what is the name for isomers of 1,2,3,4-tetrachlorocyclobutane, 1,2,3,4,5-pentachlorocyclopentane, etc? ...
14
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1answer
629 views

Why is trans-cyclooctene chiral?

How does trans-cyclooctene exhibit chirality if there are no stereocenters? Related follow-on questions: Are all higher cycloalkenes chiral? Do more double bonds cause a bigger number of ...
6
votes
1answer
187 views

R-S configuration considering stereoisomerism

How do I consider R-S configuration of this compound? On both the sides of carbon, the groups are same. They differ only in the relative position of hydrogen atoms. On what basis do I assign ...
5
votes
1answer
104 views

Determining chirality after considering conformational interconversion in a cyclohexane

Basically I want to know what does the question mean when it says "taking into consideration conformational interconversions." I assume it means, when I draw the mirror image of the given compound, ...
3
votes
1answer
246 views

Defining enantiomer of morphine by R/S designation

How to know if the following chemical structure of morphine is an R or S? What I basically need to know is: which chirality center do we use to make the decision? $\hskip2in$
4
votes
1answer
120 views

Why is 2-chloropropene achiral?

Could someone explain to me why some alkenes containing at least one couple of different substituents at the two double-bonded C atoms (that is, some of those with at least two different substituents ...
5
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1answer
196 views

Can molten sugar also rotate polarized light as sugar water does?

It is well know that the sugar water can rotate the plane of linearly polarized light, so light bends when travelling in sugar water. However, do the liquid state of sugar but not the sugar solution ...
11
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1answer
523 views

Maximum observed optical rotation through a polarimeter

Is there a maximum optical rotation of plane polarized light that can be observed using a polarimeter? I understand that in a polarimeter, light passes through a filter that converts it into plane ...
3
votes
1answer
75 views

State of a Racemic Mixture

Is a racemic mixture always an equi-molar solution of two enantiomers, both in the same state? Is it necessary for both isomers to be in the liquid state for racemisation to occur, or does ...
16
votes
3answers
480 views

How to assign E/Z configuration according to the Cahn-Ingold-Prelog rules when subsituents differ only by stereochemistry

I stumbled-upon this compound: CC=C1C(C)CCC1(C) I'm wondering how to determine the configuration of the double bond. Is it E or Z? How do I decide on the ...
2
votes
1answer
151 views

Configurations of Reactants in Second Order Nucleophilic Substitutions

The question asks me to draw the product for the reactions. However, I am stuck and do not understand how to draw the reactants with configurations correctly. (a) (S)-2-Chloropentane and NaSH I ...
2
votes
3answers
497 views

Identifying chiral centers

The compound below is fexofenadine and the only chirality center, as identified by the textbook is, the one circled in red. I do not understand why the carbon attached to the O by a double bond and ...
8
votes
4answers
2k views

How to identify a compound as chiral or achiral

I read my book and learned everything about enantiomers, racemization, $\mathrm{S_N1}$ and $\mathrm{S_N2}$ reactions, but when I'm trying to identify molecules as chiral or achiral, I get confused. ...
4
votes
1answer
121 views

Stereochemistry: R and S notation

How do we number the carbon atoms in symmetrical molecules while giving R and S notation. For instance, in 2,3-Dibromobutane, there is an ambiguity over which is carbon C2 and carbon C3. Will we call ...
2
votes
1answer
36 views

Chirality, physical or chemical property

Heyo, I was wondering whether one would consider chirality a physical or chemical property. In my opinion it should be both, because it will affect the way in which plane polarized light is interacted ...
2
votes
1answer
109 views

Can pseudochirality be considered when 3 or 4 groups on the C atom are the same?

When for example the C atom is bonded to one H, and then three more structurally identical groups with 2 chiral C each - in configurations R,R and S,S and R,S respectively - then by assigning each of ...
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0answers
85 views

Chirality vs Resonance in chemical structure

In a reference book, chirality of a molecule is explained as "handedness", like our right and left hand, which are mirror images of each other. These are also called as enantiomers. The nearest clue ...
2
votes
2answers
634 views

Chirality on Propranolol

I'm a bit confused when asked to specify the chiral carbons on this sketch of Propranolol as I'm not sure how the $\ce{H3C}$ and $\ce{CH3}$ play in if they are reversed in the name like that...Does ...
2
votes
2answers
44 views

Is there anything akin to molecular chirality for crystalline?

For example, in hexagonal closed-packed (HCP) structure, the atoms may be arranged in ABAB stacks or ACAC stacks. Can these two be considered enantiomers? Do they possess different solid state ...
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2answers
4k views

Are all amino acids except glycine chiral compounds?

Specifically, I was thinking of the case where the R group is a carboxylic acid functional group or an amine group. Then there would not be a chiral carbon atom. Is there a restriction on what can be ...
3
votes
1answer
102 views

Is bicyclo[1.1.0]butane chiral?

Is bicyclo[1.1.0]butane chiral? I think it isn't, but if one of the hydrogen atoms bound to the tertiary or secondary carbon atoms is replaced with e.g. chlorine, the formed compound will be chiral, ...
2
votes
4answers
123 views

Gas phase chiral molecules

Are there any molecules that are chiral that are also gases at room temperature? Failing that, what chiral molecules have a high vapor pressure? Propylene oxide has a boiling point of only 34 C, so ...