Optically active and inactive

[deleted883500]

I was reading my orgo textbook and dont understand this part:

I thought that only optically active reagents and catalysts could produce optically active products. Here I only see an achiral molecule that produces 2 chiral molecules (being chiral means it is optically active right?)

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[Dentalco2020]

I believe if you have a solution of chiral molecules (either R or S) you will have optical activity.
If you have equal mixture of R and S, this is called racemic mixture, then the optical activities of R and S cancel each other, hence no optical activity.

In short, chiral molecule = optically active Achiral molecle = optically inactive


To answer your specific question, I don't recall reading anything saying that it has to be catalyst or optically active reagent to create a optically active molecule. Of course, I can be very wrong about this, but for the purpose of DAT, I think it's safe to assume chiral = optically active

 

[DAT Destroyer]

I was reading my orgo textbook and dont understand this part:
View attachment 224503
I thought that only optically active reagents and catalysts could produce optically active products. Here I only see an achiral molecule that produces 2 chiral molecules (being chiral means it is optically active right?)

The statement must be made in the proper context and refers to a particular mechanism that you are studying. If for example, you are doing an SN1 reaction using t-butyliodide..an optically INACTIVE molecule ,,,,,,,reacting with methanol........We form the carbocation, then attack, and then get the ether product. The starting material was optically inactive, hence so is the product. The same logic would apply to the SN2 process. Now.....if either was optically active, we could indeed get an optically active product..or easily obtain it from racemic separation if needed. The reaction that you show illustrates what happens when there are 2 different " faces " to a molecule..... One face is more easily accessible to a nucleophile than the other. Thus the optically inactive compound did indeed produce a result that gave optical activity. This is neither an SN1 or SN2 reaction....However, as a general rule of thumb, an optically inactive compound gives an optically inactive product. It is indeed a BROAD statement as you called it out. Focus on the chemistry for the DAT and not so much on the semantics of organic chemistry parlance. Feel free to join my FB DAT study Group to discuss this further.

Hope this helps.

Dr. Romano