joonkimdds

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This is Q33 from Destroyer.
It says the first one produces enantiomer only whereas the second reaction produces diastereomer.

I drew the products and I think both reaction produce enantiomer only.
Products for the first rxn are mirror image to each other.
Products for the second rxn are mirror image to each other, too.

diastereomer means non-mirror image, non superposable but they are mirror image so how can we say that the products for the 2nd reaction are diastereomers?
 

zuma35

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This is Q33 from Destroyer.
It says the first one produces enantiomer only whereas the second reaction produces diastereomer.

I drew the products and I think both reaction produce enantiomer only.
Products for the first rxn are mirror image to each other.
Products for the second rxn are mirror image to each other, too.

diastereomer means non-mirror image, non superposable but they are mirror image so how can we say that the products for the 2nd reaction are diastereomers?
The methyl group will be either a solid wedge or a dashed wedge. Assuming it's a solid wedge - that won't change when you add the Br2. So you will get the two products that you wrote, but the methyl will be a solid wedge in both, and the two products will not be mirror images.
 

doc3232

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This is Q33 from Destroyer.
It says the first one produces enantiomer only whereas the second reaction produces diastereomer.

I drew the products and I think both reaction produce enantiomer only.
Products for the first rxn are mirror image to each other.
Products for the second rxn are mirror image to each other, too.

diastereomer means non-mirror image, non superposable but they are mirror image so how can we say that the products for the 2nd reaction are diastereomers?
I don't think the second pair are mirror images.
 
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joonkimdds

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I think there are 3 ways to draw mirror; right, bottom, and behind(toward the paper).
Anyway, assuming that methyl group is wedged or dashed, I guess that makes sense.

Should I always assume that carbons that are not part of cyclo structure or the parent hydrocarbon chain (longest chain) can be wedged or dashed?
 

zuma35

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I think there are 3 ways to draw mirror; right, bottom, and behind(toward the paper).
Anyway, assuming that methyl group is wedged or dashed, I guess that makes sense.

Should I always assume that carbons that are not part of cyclo structure or the parent hydrocarbon chain (longest chain) can be wedged or dashed?
Not always - only when the carbon that's connecting it has sp3 hybridization. Do you have molecular models? You'll see that the the methyl group will be pointing either towards you or away.
 
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