[AlphaScent]

My professor also gave this question.  With no reagents and no way to push electrons from either the oxygen or nitrogen...I am up a creek.  Befuddled if you will. 

[Dan]

Hint: Aminal

[orgopete]

I'm not sure of Dan's reaction (nor mine), but given that this example has chirality and you posted another reaction in which a chiral auxiliary was used, I'm going to assume an "uncatalyzed" cyclization occurs to give a chiral product.

[AlphaScent]

Dan,

That was my initial thought too.  The problem for me was that there is now acid present to open up the aminal.  I guess it may do it under heat.  The delocalization of the nitrogen lone pair due to it being an amid also bothers me.  I came up with something.  I will ASAP

[AlphaScent]

My Attempt.  I think it is crap.  You need acid. Catalytic.  Even the glass would be a source.

[orgopete]

Since you are making the enamine from the iminium ion, I think enolization of the aldehyde is possible. I'd have it add to the carbonyl group. Since the groups attached to it are different, I'm expecting a selective addition. Also, since it is heated, elimination of water. Now that I am thinking about it, I would tell students that "heat" was a key to expect elimination. Also, could the problem have an error, such as a missing reagent?

[AlphaScent]

I considered enolization, but the addition would give the wrong product.  Alpha carbon to aldehyde would add (enolate).  I mentioned the tough time I was having and my professor..."thats easy"

I do not think there is a missing reagent

[orgopete]

Ah, yes, you had given the product. When I was looking at the scheme, it conveniently showed the reaction arrow and conditions but I have to scroll to see the product. I was predicting a different product.

[Dan]

Alphascent, I think your mechanism is plausible. I would proton transfer to the alkoxide in the enamine formation step, otherwise this is exactly what I had in mind.