[Moz29386]

Dear Users,

I'm trying to find out what will happen to the cis and trans isomer of this compound http://www.chemicalregister.com/upload/cr/94-60-0.png after it goes through the acyloin reaction.

It reacts with 4Na and TMS giving a cyclised ditms ether.

The Question: One isomer of this compound reacts, the other isomer doesn't react. Explain and identify why?

I think the trans isomer doesn't react because when the diradical is created the carbons are not facing the same way in order to form a new bond whereas the cis has both carbons facing the same way so the new sigma bond can be formed???

Please help, I'm certain this is one of my exam questions.

Thanks!

[orgopete]

I sort of agree. The trans will not form an intramolecular product for the reasons stated. That it would not react at all, I doubt that. It just wouldn't give the bicyclic product.