[Altered State]

Hi there,
I've drawn in chemdraw what I have done for this problem, so is easier to explain:



What I have to do is in the top of the img, justify the formation of that product in that reaction.

Well, in my opinion the reagents of this reaction would undergo transformations like I've drawn them, to give a different product, not the one I'm supposed to justify.
I understeand that that reactions can go by so many different pathways, (different enolates, different carbonyls...), but, as I have drawn in the bottom of the img, the product of the exercise should've come from the compound I've named "Preproduct". The problem is that I don't see how that molecule could have been formed from a robinson annulation, doesn't make sense to me, since there is no carbonyl in alpha to the carbon attached to the O(-).

Is there any other reaction that I'm not seeing? Maybe any transposition?
Or it's just that this is imposible and the product compound is drawn wrong? (That would be the third molecule in this exercise sheet wrongly drawn)

Hope you can help. Regards

[discodermolide]

In equlibrium 3 you have drawn the carbonyl in the wrong place.

Move it up by one carbon atom (in the 6-membered ring)put the OH back and re-do the water elimination.
Your mechanism is OK, but your drawing is a bit skewed,
You should get

[Altered State]

In equlibrium 3 you have drawn the carbonyl in the wrong place.

Move it up by one carbon atom (in the 6-membered ring)put the OH back and re-do the water elimination.
Your mechanism is OK, but your drawing is a bit skewed,
You should get

Wops, stupid of me, thank you.