[Penguinone]

Question: Provide mechanism for the reaction shown in the picture below.

Attempt: See below.

I've really got no clue what I'm doing with this question.

Any help will be greatly appreciated.

[orgopete]

Hint, the desired product forms FROM a Claisen condensation. Second hint, how can this starting material form a diester?

[zsinger]

What is this step where the double bonds grabs a methyl group.  As a good rule of thumb,H- nor CH3- is ever kicked off as a leaving group (save haloform reaction for CF3 or CCl3 etc.), as they are so poorly resonance stabilized in solution.  That step is surely not correct, as "CH3-" would have to float around in solution for a moment in time (not a happy molecule).  Building on what Orgopete said, the best way to look at this is to look up a Claisen, study its configuration, and then look how it is very similar to something which you have, albeit not in the correct for yet.  Hope this helps. 

[Penguinone]

Thanks for the replies. I'm still very stuck, see second attempt below.

[orgopete]

Another hint, there are more additions to the carbonyl group than enolizations. Claisen condensation reactions stop because the product is more acidic than starting materials. In this case, that is not true. Hint number two, retro Claisen.