[poorstudent83]

Hi,

I'm looking for a mechanism for the attached reaction. Every mechanism i come across results in the formation of an alkene...any help would be appreciated!

[Arctic-Nation]

That's because dehydration is the preferred mechanism. Even though I'm not familiar with any of them, methods exist for the selective reduction of the alkene part of enones. If they would work with a strained system such as yours remains to be seen, however.

[nj_bartel]

Protect the alcohol, acetal, deprotect, oxidize, wolff-kishner, go back to carbonyl.  Pretty rough conditions for that ring I guess.  Probably wouldn't make it past the oxidation.

[Dan]

I'm looking for a mechanism for the attached reaction. Every mechanism i come across results in the formation of an alkene...any help would be appreciated!

Do you know this reaction works or is this your own suggested strategy?

That's because dehydration is the preferred mechanism.

Even in a four membered ring? Cyclobut-2-enone has three sp² centres in a four membered ring - that's super strained and could quite plausibly direct the reaction towards nucleophilic substitution. I'm just speculating here though.

What about triflation/mesylation etc. followed by iodide followed by H₂/Pd? 

[azmanam]

barton-mccombie's a one-stepper (two if you have to isolate the xanthate ester)

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

[poorstudent83]

I apologise if I've annoyed anyone but the structures I've displayed are wrong. It's actually a very large ring (proper structures attached). Again, I apologise for the error! I've seen this reaction in a paper and am very curious about its mechanism.

[Sam (NG)]

I apologise if I've annoyed anyone but the structures I've displayed are wrong. It's actually a very large ring (proper structures attached). Again, I apologise for the error! I've seen this reaction in a paper and am very curious about its mechanism.

don't suppose you have the DOI for the paper?

[Arctic-Nation]

Even in a four membered ring? Cyclobut-2-enone has three sp² centres in a four membered ring - that's super strained and could quite plausibly direct the reaction towards nucleophilic substitution. I'm just speculating here though.

It's been done using the bromo derivative and an amine base, so it's at least a possibility.

[poorstudent83]

Problem solved, the reaction was taken from a review. On inspection of the original paper, I found that the reaction in the review was incorrect. Apologies to everyone!