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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: g_orbital on May 29, 2007, 05:01:02 AM

Title: cyclopropane reductive opening with Li/NH3
Post by: g_orbital on May 29, 2007, 05:01:02 AM

The following reaction exploits Lithium + ammonia in order to cleave the cyclopropyl ring. Usually, I'm used to see these reagents as "Birch condition" for reduction of aromatic compounds or alpha,beta-unsaturated ketone. But here, I fail to understand the mechanism of the reaction (It seems radical, however).

I'll appreciate your assistance.
Thank you

Title: Re: cyclopropane reductive opening with Li/NH3
Post by: miraculix on May 29, 2007, 07:10:55 PM

Hello,

I would suppose you're generating a Ketyl-radical under these reaction conditions.
Therefore, you will have a cyclopropyl-ketylradical.
These radical are known to undergo a very fast (one of the fastest) ring opening reactions.
The same would probably happen with SmI₂.

cheers
miraculix