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Topic: chirality center  (Read 1900 times)

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Offline orgo814

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chirality center
« on: October 08, 2012, 10:27:48 PM »
Can someone please explain why the chirality center in the first enantiomer is R (on attached picture)? I don't see it. The highest priority is the oxygen which is pointing out while the hydrogen (lowest priority) is pointed back... that's how we want it. The ring would be the second highest priority and the one leading to the amine is the third. I get that.

When I look at it, I see it going to the left not right so I can't see how it's R and not S? Please be specific in your answer- any help appreciated.

Offline orgo814

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Re: chirality center
« Reply #1 on: October 08, 2012, 10:28:59 PM »
Oh wait would the one leading to the amine be the second highest priority? that's probably my problem

Offline discodermolide

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Re: chirality center
« Reply #2 on: October 08, 2012, 10:32:13 PM »
I was just about to say that!
Development Chemists do it on Scale, Research Chemists just do it!
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Offline orgo814

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Re: chirality center
« Reply #3 on: October 08, 2012, 10:41:19 PM »
thanks anyways!

Offline fledarmus

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Re: chirality center
« Reply #4 on: October 09, 2012, 07:56:07 AM »
The hardest thing about assigning priority is to remember to go ONE ATOM AT A TIME!

The first atom on the ring side is a carbon. The first atom on the amine side is a carbon. NO DIFFERENCE YET

The second atoms on the ring side are all carbons - three of them. The second atoms on the amine side are two hydrogens and a nitrogen. Nitrogen is the highest priority of all six of the second atoms. Amine side is higher priority

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