Chemical Forums

Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: optimusprime on February 10, 2008, 04:46:33 PM

Title: Reversible ozonolysis
Post by: optimusprime on February 10, 2008, 04:46:33 PM
What do you say, is ozonolysis reversible?  That is, from two carbonyls can you form an alkene and Ozone?
Title: Re: Reversible ozonolysis
Post by: macman104 on February 10, 2008, 05:13:56 PM
I don't believe ozonolysis is reversible...but that's more a guess than anything.
Title: Re: Reversible ozonolysis
Post by: optimusprime on February 10, 2008, 05:32:00 PM
It was a fevered dream more than anything.
Title: Re: Reversible ozonolysis
Post by: movies on February 10, 2008, 05:33:51 PM
Well, you can do the reverse transformation, but it doesn't make ozone.

The reaction is called a pinacol coupling, sometimes also called an acyloin coupling or a McMurry coupling.  Messy reactions though.
Title: Re: Reversible ozonolysis
Post by: sjb on February 11, 2008, 02:38:25 PM
Well, you can do the reverse transformation, but it doesn't make ozone.

The reaction is called a pinacol coupling, sometimes also called an acyloin coupling or a McMurry coupling.  Messy reactions though.

I thought a pinacol was 2 x carbonyl -> diol, and similarly acyloin 2 x carbonyl -> hydroxy carbonyl ?

Agreed though, these can be fairly messy

S
Title: Re: Reversible ozonolysis
Post by: movies on February 11, 2008, 10:54:26 PM
True, I guess the pinacol part isn't the whole transformation, but it does make the C-C bond.  Then you can take the diol to an olefin by Corey-Winter reaction or something.
Title: Re: Reversible ozonolysis
Post by: zeoblade on May 27, 2011, 09:12:51 PM
I'm sorry to dig up an old thread but I feel its really relevant.

I understand Ozonolysis can clean an alkene into 2 ketones but what if I wanted to do the reverse?

If I had 2 ketones, how can I do reverse ozonolysis to make and alkene without being messy and in good yield? For example, if I wanted to join 2 molecules of cyclohexanone?

Title: Re: Reversible ozonolysis
Post by: nox on May 28, 2011, 01:39:19 AM
McMurry coupling