- Joined
- Jul 18, 2008
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I'm 'relearning' (learning) absolute configuration and I still suck at it.
For the trans molecule, I understand why the top stereocenter is R. The hydrogen is already facing away. Priority in decreasing order is: chlorine, CClH, CH2, and that's clockwise so it's R.
The bottom stereocenter I don't get. H is facing toward me so couldn't I just switch Cl and H to give me this (pardon my crap mspaint skills):
Priority in decreasing order is: chlorine, CClH, CH2, which is counterclockwise or S...but it says R! What am I doing wrong?

For the trans molecule, I understand why the top stereocenter is R. The hydrogen is already facing away. Priority in decreasing order is: chlorine, CClH, CH2, and that's clockwise so it's R.
The bottom stereocenter I don't get. H is facing toward me so couldn't I just switch Cl and H to give me this (pardon my crap mspaint skills):

Priority in decreasing order is: chlorine, CClH, CH2, which is counterclockwise or S...but it says R! What am I doing wrong?