[andorrak]

Hi I have absolutely no idea how to tackle this one problem.

Acetic Acid with Toluene(won't do anything here) at 110 C. with the reagents of morpholine and cyclohexanone.

Any link with reading will be much appreciated. I am off campus and just have the damn lecture notes.

[andorrak]

Will I get a condensation of the two? What I'm thinking is that the acid will allow the N to attack the carbonyl creating water and a double bond on the cyclohexane.

So its like a double ring with the nitrogen attached the cyclohexene.(would be an alkene at that point.)

If anyone wants to confirm that would be great.



Wanted to edit the above.

Acetic acid attacks the carbonyl. carbocation on carbon holding the OH. N moves in, creates h2o(There's obviously still an OH attached but it pulls away.)

so you would get 1-morpholino 1 cyclohexanone? I think thats correct IUPAC

[orgopete]

I don't know what is in your notes, but you can find the enamine formation here:
http://www2.chemistry.msu.edu/faculty/reusch/VirtTxtJml/aldket1.htm#rx1c

Reusch also has a button that shows a mechanism. However even though the mechanism does succeed in arriving at the enamine, I do not think this is a good mechanism.

[OC pro]

The mechanism at the Reusch group page is correct. 

[orgopete]

The problem with it, is that it seems unlikely (to me) that a carbonyl group will become protonated in an excess of an amine. I think an amine can add to a carbonyl group without an acid catalyst. Aminals form from aldehydes and amines under basic conditions, potassium carbonate. I think the acid is more likely to protonate the OH of the adduct. I think this is more in line with the known optimum pH for oxime formation, pH 4. Again, I presume this is to encourage the loss of water. Lower pH's tie up the amine and high pHs resist loss of water (I presume). If the pH of the solution was as low as to protonate a carbonyl group, I would expect it would also tie up all of the amine.

I don't think this is a big deal. The remainder of the mechanism would be the same. I just think one has to be careful in using the acids that are likely present, in this case an ammonium salt. I don't think you can catalyze a ketalization with triethylammonium acetate or tosylate for example, especially if you have an excess of amine. I don't know that, but I just don't think that is acidic enough. I think you can add to a carbonyl group with an alcohol and an amine, for example, ethanol, TEA, and acetic anhydride.

[OC pro]

Remember that this is in equilibrium! So a tiny amount of ketone can be protonated. I´m not sure which step is the rate-determining one. But I´m sure that loss of water will be very fast due to entropic reasons. So I assume that acid will catalyze attack of amine to ketone.
A mechanism is always a proposal...