Author Topic: cis and trans  (Read 1407 times)

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amalgum

  • Guest
cis and trans
« on: September 30, 2001, 08:34:00 PM »
What is the difference between the cis and trans isomers of safrole other than them being structured different.  Is one more potent than the other?

terbium

  • Guest
Re: cis and trans
« Reply #1 on: September 30, 2001, 09:43:00 PM »
The better question might be - what is the difference in reactivity of the safrole cis and trans isomers during a Wacker oxidation. To which the answer would probably be - not much.

Cis and trans safrole both convert into exactly the same ketone. So once you have the ketone the difference is gone.

amalgum

  • Guest
Re: cis and trans
« Reply #2 on: September 30, 2001, 10:15:00 PM »
Actually I wasnt worried about reactivity.  I was just wondering if use of a different isomer would yeild a better product in the long run.  But since you brought it to my attention that it goes to the same ketone, I guess all I can say is nevermind.

foxy2

  • Guest
Re: cis and trans
« Reply #3 on: September 30, 2001, 11:17:00 PM »
Terbium

I think  I saw a reference that said the reactivity of the cis was somewhere around 9 times faster than the trans.   If I remember right it was for an epoxidation reation. Don't quote me on this because my memory is foggy and I have no idea where I read it.
:)

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terbium

  • Guest
Re: cis and trans
« Reply #4 on: October 01, 2001, 12:53:00 AM »
:-[ Whoops, quite correct.

riobard

  • Guest
Re: cis and trans
« Reply #5 on: October 01, 2001, 12:09:00 PM »
Foxy,

   I think you're right about the rate being 9X faster for cis-isosafrole than trans-isosafrole. The cis- isomer is a bit less hindered for the peracid to approach the isosafrole molecule's double bond, so it should react more quickly. Epoxidations only goe through a single step, so no wierd chemistry in involved as far as I can see.