orgo chem question - confused

[lazyindy]

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I think this compound is chiral because it would be non-superimposable on its mirror image. However This time we are dealing with an alkene

any thoughts?

 

[Lnguyen7]

The compound has a plane of symmetry, so it is achiral and E configuration.

 

[Incis0r]

The compound has a plane of symmetry, so it is achiral and E configuration.

Where is the plane of symmetry? I don't see it..

 

[Lnguyen7]

Where is the plane of symmetry? I don't see it..

I might be wrong, but the way I see it is using the box surrounding the molecule as a mirror; the top and bottom are identical.

 

[RuffDay]

I think it is achiral and E configuration as well. There isn't any chiral center in this molecule.

 

[Incis0r]

I might be wrong, but the way I see it is using the box surrounding the molecule as a mirror; the top and bottom are identical.

Ohh; I was under the impression that you had to have an internal plane of symmetry for achirality- will explore more, thank you!

 

[DrNutmeg]

I believe the answer is C. We can all see that it is E configuration, but is it chiral or achiral? I believe it is chiral; We can see that it is chiral because all 4 substituents on the alkene are different, and therefore there is no plane of symmetry.

Lazyindy, do you have the answer?

 

[RuffDay]

I believe the answer is C. We can all see that it is E configuration, but is it chiral or achiral? I believe it is chiral; We can see that it is chiral because all 4 substituents on the alkene are different, and therefore there is no plane of symmetry.

Lazyindy, do you have the answer?

I thought alkenes cannot be chiral since it is sp2. The only exceptions are biphenols and allenes. Since they both have a fixed configuration, and it cannot be rotated.

 

[100%permwinner]

I do not see any sp3 carbon bonded to 4 different atoms, so it cannot be chiral. Two different groups bonded to same side of alkene, the configuration is E.

 

[DrNutmeg]

I thought alkenes cannot be chiral since it is sp2. The only exceptions are biphenols and allenes. Since they both have a fixed configuration, and it cannot be rotated.

The entire alkene acts as the chiral center. Just like in a chiral center, the alkene has 4 substituents. If all 4 are unique, it is a chiral center.

 

[Lnguyen7]

Here's why I think it is achiral. A molecule that is achiral if it is superimposable on its mirror image. So lets draw its mirror image and see whether they are superimposable. Some hydrogen were drawn for illustration.

 

[FeralisExtremum]

The entire alkene acts as the chiral center. Just like in a chiral center, the alkene has 4 substituents. If all 4 are unique, it is a chiral center.

While cis/trans alkenes count as chiral centers for the purposes of determining the total possible number of stereoisomers, a cis/trans molecule by itself is not chiral. I think Lnguyen7 is correct - it looks achiral to me. No chiral centers and it's superimposable with its mirror image.

 

[DrNutmeg]

Here's why I think it is achiral. A molecule that is achiral if it is superimposable on its mirror image. So lets draw its mirror image and see whether they are superimposable. Some hydrogen were drawn for illustration.

Okay, I'm convinced.

 

[Incis0r]

Here's why I think it is achiral. A molecule that is achiral if it is superimposable on its mirror image. So lets draw its mirror image and see whether they are superimposable. Some hydrogen were drawn for illustration.

Case closed 😀 Thank you Lnguyen!

 

[DAT Destroyer]

I think this compound is chiral because it would be non-superimposable on its mirror image. However This time we are dealing with an alkene

any thoughts?

View attachment 193840

This molecule has the E configuration. There is indeed a STEREOCENTER...... A .stereogenic center is an atom bearing groups such that an interchanging of any two groups leads to a stereoisomer.

Here, the E and the Z would represent stereoisomers called diastereomers. There are no enantiomers.

However....the molecule is not optically active. You do not have a chiral atom here.

Hope this helps

Dr. Romano

 

[lazyindy]

This molecule has the E configuration. There is indeed a STEREOCENTER...... A .stereogenic center is an atom bearing groups such that an interchanging of any two groups leads to a stereoisomer.

Here, the E and the Z would represent stereoisomers called diastereomers. There are no enantiomers.

However....the molecule is not optically active. You do not have a chiral atom here.

Hope this helps

Dr. Romano

thanks Dr. Romano!