R,S config

[Moka11]

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What makes the middle ethyl S?

Why isn't it from 1 C-OH >2 Ethyl > 3 C-attached to Methyl? Which is clockwise and an R?


(1R,2S,3S)-2-ethyl-3-methylcyclohexanol

 

[KyoPhan]

I believe the ethyl is the 3rd priority.

For the top group, it is a carbon attached to only 1 carbon.
For the right group, it is carbon attached to 2 carbons(One of them being from the methyl group. The second is part of the ring).

The carbon with 2 carbons attached to it will get a higher priority than the other with only 1 carbon attached.

Clockwise is R. It goes counterclockwise, so it is S.

 

[Moka11]

I believe the ethyl is the 3rd priority.

For the top group, it is a carbon attached to only 1 carbon.
For the right group, it is carbon attached to 2 carbons(One of them being from the methyl group. The second is part of the ring).

The carbon with 2 carbons attached to it will get a higher priority than the other with only 1 carbon attached.

Clockwise is R. It goes counterclockwise, so it is S.

Oooooohhhh 😳
Thanks!