[Wisemanleo]

The reaction I'm trying to set up is based on Chao-Jun Li's paper on Aldol- and Mannich-Type reactions via in situ olefin migration in an ionic liquid (Org Lett, Vol 5, No 5, 657-660, 2003).

Basically, the change that I'm making is that instead of an aldehyde, I'm using 2-butanone. And instead of a schlenk vessel, I'm using a small sealed vial with some teflon tape around the cap.

Obviously, this didnt work out. HNMR shows starting materials among some other junk. But it's puzzling because the reaction *should* work. So I wonder if its really just the 2-butanone not being reactive enough, or is the sealed cap technique shabby enough to ruin the reaction?

[Mitch]

How many more peaks do you see in TLC, Have you ran a Mass spec just to see if perhaps the product was made as well?

[Wisemanleo]

On TLC, I see one spot that corresponds to my PMP group (which, for some reason, likes to jump off), one spot for my imine, and the spot for my product.

I haven't run a mass spec yet though. Is it worth the time, despite the fact that my HNMR doesn't show the key characteristic peaks that I'm looking for?

[Mitch]

What do you mean you see your product. I usually always use NMR and mass spec in conjuction, one analytical method is simply not enough sometimes. Plus a mass spec has higher sensitivity. So if your reactants is a 100 times more concentrated than your product, those peaks will be drowned out in an NMR. A 1% yield is nothing to write home about, but still.

[kiwi]

2-butanone is much less reactive than an aldehyde, try the reaction with a  reactive aldehyde (eg. benzaldehyde, or something the reaction is known to work with), to check that the other reagents are fine. but bear in mind, people don't usually use schlenkware just for the fun of it.

edit: and not that i don't think the approach isn't neat, but there are of course other perfectly good, more traditional methods to get to those sorts of compounds

[Wisemanleo]

When I said I see one spot corresponding to my product, I meant that I just see a new spot. So I know something happened. So I definitely should try out mass spec'ing it.

I know benzaldehyde works, so I might go the route of using the enol silyl ether equivalent of 2-butanone...