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Topic: E2 Mechanism Question  (Read 2380 times)

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Offline aspiringphysician

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E2 Mechanism Question
« on: June 19, 2012, 08:27:45 PM »
I am having trouble figuring out the mechanism for this question:

"The first step in the reaction (pictured below) is the formation of the conjugate base of the starting material. This intermediate will proceed through an E2-type mechanism where CO2 is lost in place of a proton. Provide a step-by-step electron-pushing mechanism that accounts for the stereochemistry.  Use perspective representations throughout.  Clearly show and name (E/Z) the stereochemistry of the product."

Are they talking about the conjugate base of K2CO3? And I don't understand how CO2 is lost...does the base take it? Then how does the carboxylic acid proton stay attached to the substrate?  ???
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Offline fledarmus

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Re: E2 Mechanism Question
« Reply #1 on: June 19, 2012, 08:31:53 PM »
No, the conjugate base is what you get when the acid loses a proton.

Offline aspiringphysician

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Re: E2 Mechanism Question
« Reply #2 on: June 19, 2012, 11:22:15 PM »
Ah, okay...thanks, I figured it out now!...and, by the way, the alkene on the right should have been cis, not trans  :P
"Now, before you get all 'high-and-mighty', remember that some PLANTS have more complex genomes than YOU!" ~ Dr. Linn

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