R-S configuration question

[shoot4greatness]

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Hi all,

My exact question is based on the image attached. Why did they go counterclockwise? I would have gone clockwise to follow 1, 2, 3. Does it have something to do with the stereochemistry about that carbon? Thanks for help!

 

[image187]

I believe you're supposed to rank the groups attached to the chiral atom first... and then the order of the groups will either be clockwise or counterclockwise. From here you can tell if the molecule is R(D) or S(L)

 

[image187]

I believe you're supposed to rank the groups attached to the chiral atom first... and then the order of the groups will either be clockwise or counterclockwise. From here you can tell if the molecule is R(D) or S(L)

 

[brood910]

Is that a typo? 3 is supposed to be 2 here since it has alkyl group attached instead of H.

 

[sdm33]

Yes, the numbers are listed at the wrong order, C1 is correct, But I think they switched C 2 and C3
they put the wrong numbers at the wrong places.
C2 is is the one connected to O and C
C3 ---- O and two Hs

 

[shoot4greatness]

Thanks, guys. It definitely looks like a typo now to me, too.

 

[shoot4greatness]

Hey guys,

Can you help me determine priorities of the molecule in the picture attached? Please explain how you chose each priority, if possible. Thank you!

 

[brood910]

Hey guys,

Can you help me determine priorities of the molecule in the picture attached? Please explain how you chose each priority, if possible. Thank you!

1S, 1S.

The methyl group is on the dash line, which means H is not on the dash. You have to reverse the configuration as a result.

 

[shoot4greatness]

1S, 1S.

The methyl group is on the dash line, which means H is not on the dash. You have to reverse the configuration as a result.

Can you tell me how you chose each priority for the two chiral centers?