AAMC7: What the heck Orgo question.

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pfaction

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How the hell does a Phosp Ylide make a double bond???
I guessed because I have no idea what was going on in this section.

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Basically: Wittig reaction swaps out a C=O fro a C=C.

If you ever see a question asking "How do we convert a ketone/aldehyle to an alkene?" Look for the ylide.

Anyway, you asked "how"

Notice that the ylide has 3 phenyl group and a phosphorus attached to a CH2 group. If you look up the structure you'll actually see it's a zwitterion with a negatively charged CH2 group. So ylide = carbanion= nucleophile.

So the ylide will act as a nucleophile and attack the electrophilic carbonyl carbon. That's how the new carbon-carbon bond is formed that yields the formation of an alkene.
 
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Lol, don'y worry. I know the witting reaction pretty well and I was like WHAT THE **** HOW IS THAT WORKING?

Turns out I was looking at compound 3, as indicated.
 
haha, pfaction i have feeling you're hilarious. anyone who studies with you in medschool will have a good time
 
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