[webassignbuddy]

^ The answer to this isn't this:



Is the answer this:

[discodermolide]

No it's not the ketene.
What else can happen to the anhydride upon base treatment?

[webassignbuddy]

No it's not the ketene.
What else can happen to the anhydride upon base treatment?

I have absolutely no clue...
This reaction isn't in any of my teachers' slides

[discodermolide]

How about attack of the ethoxide at a carbonyl with ring opening?

[webassignbuddy]

How about attack of the ethoxide at a carbonyl with ring opening?

Is that the answer?
At the bottom of the question there's a hint that says "There is NO acid workup"

[discodermolide]

Not quite, what happened to the ethoxide group and where is the Na⁺, if there is no acid work-up?

[webassignbuddy]

Not quite, what happened to the ethoxide group and where is the Na⁺, if there is no acid work-up?

I have no idea...

1) The OH attacks the the left or right carbonyl.
2) 2 electrons are pushed onto the carbonyl's oxygen and then gets a negative charge
3) 2 electrons from that oxygen get pushed back down to kick out the ring's middle oxygen, which will now have a negative charge
4) Then that oxygen deprotonates the OH that was added, right? so I would get this....



And than the O with the negative charge attacks the Na+?



But that doesn't look right, considering all of the other problems ive gotten right doesn't even have answers containing Na

[discodermolide]

what about this compound?

[webassignbuddy]

what about this compound?

I...don't get it...how does the O get the ethyl group on it?
Is there another pushing mechanism for this?

[webassignbuddy]

Ohhhhhhhh

Na+ and OCH₂CH₃-

Gotcha....
thanks!

[orgopete]

Ohhhhhhhh

Na+ and OCH₂CH₃-

Gotcha....
thanks!

Of course, that is why we emphasis mechanisms. With a mechanism, it seems implausible the ethyl group wouldn't be connected.