Qpack Chem #8

[laczlacylaci]

The answer is only 5, which yes I agree is a stereocenter.

Why is 2 not a stereocenter?

@aldol16 (I chose this answer bc of the ucla article you sent me. Is it because it is in a ring?)
If the double bond existed by itself, would it have been a stereocenter?

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[aldol16]

@aldol16 (I chose this answer bc of the ucla article you sent me. Is it because it is in a ring?)

For others, here is a synopsis of the stereocenter article: http://www.chem.ucla.edu/~harding/IGOC/S/stereocenter.html

The answer has to do not with what is or is not a stereocenter but which stereocenter gives rise to the (+) or (-) designations. (+) and (-) refer to enantiomers, which are non-superimposable mirror image versions of each other. The only relevant stereocenter is thus 5.

 

[LIC2015]

View attachment 208029
The answer is only 5, which yes I agree is a stereocenter.

Why is 2 not a stereocenter?

@aldol16 (I chose this answer bc of the ucla article you sent me. Is it because it is in a ring?)
If the double bond existed by itself, would it have been a stereocenter?

Stereocenters need four constituent groups (someone please correct me if I'm wrong). Only carbon 5 has four different bonded groups.

 

[laczlacylaci]

For others, here is a synopsis of the stereocenter article: http://www.chem.ucla.edu/~harding/IGOC/S/stereocenter.html

The answer has to do not with what is or is not a stereocenter but which stereocenter gives rise to the (+) or (-) designations. (+) and (-) refer to enantiomers, which are non-superimposable mirror image versions of each other. The only relevant stereocenter is thus 5.

oh what a silly mistake. I keep having you at the back of my head when I'm doing ochem problems

 

[laczlacylaci]

Stereocenters need four constituent groups (someone please correct me if I'm wrong). Only carbon 5 has four different bonded groups.

For this question since it is solely reliant on enantiomers, then yes it is C5 (4 different groups). But Stereocenters are different than chirality, in which it can have other rules. Check out the last 3 problems in the article presented above.