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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: tomhall15 on December 15, 2010, 01:27:18 PM

Title: Mechanism to form epoxide!!
Post by: tomhall15 on December 15, 2010, 01:27:18 PM

I am some difficulty solving this problem:

Propylene oxide (epoxypropane) is produced on an industrial scale from propylene (propene) using the reagent known as "m-CPBA" or "mCPBA": meta-chloroperbenzoic acid (3-chloroperoxybenzoic acid).

Outline a detailed mechanism for this industrial process. No other reagents than those given are necessary. (Use electron-flow arrows to indicate the movement of electrons in the template to the left of the reaction arrow, then modify the template to the right of the reaction arrow to show the resulting product(s). Assign lone pairs, radical electrons, and atomic charges where appropriate. Do not add atoms to or remove atoms from the template.)
(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Fi947.photobucket.com%2Falbums%2Fad317%2Ftomhall15%2Fepoxide.jpg&hash=cadd6d776155c780e6687c1470ed919ea1f2a751)

I have already tried this and I don't know why I got it wrong... (https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Fi947.photobucket.com%2Falbums%2Fad317%2Ftomhall15%2Fepoxide1.jpg&hash=e2ade66d0df8785850491b9bfdab9beae4fb28d3)

THANK YOU in advance!!

Title: Re: Mechanism to form epoxide!!
Post by: MissPhosgene on December 15, 2010, 04:29:49 PM

They might be expecting you to draw the transition-state?

Title: Re: Mechanism to form epoxide!!
Post by: ooosh on December 15, 2010, 10:15:41 PM

Dont draw a mechanism in one step.

Title: Re: Mechanism to form epoxide!!
Post by: Hybrid on December 15, 2010, 11:56:14 PM

it is concerted mechanism give to butterfly transition state see Prilezhaev reaction

http://www.organic-chemistry.org/namedreactions/prilezhaev-reaction.shtm

Title: Re: Mechanism to form epoxide!!
Post by: orgopete on December 16, 2010, 01:41:52 AM

Count your carbons.

Title: Re: Mechanism to form epoxide!!
Post by: jake.n on December 16, 2010, 03:22:36 PM

Look carefully around the peroxide oxygen.  With the arrow pushing you show, you do not create an octet around this oxygen.

So, where did your electrons go from the peroxyacid hydrogen?