[Steenrod]

My friend and I are having an argument over this:

When methyl glyoxal is treated with 50% NaOH,what will happen?

I say it is Aldol condensation as there are 3 alpha hydrogens present.Am I correct?

Is the final product [itex]CH_3COCH(OH)CH_2COCHO[/itex]?

[Dan]

I think there are quite a number of possibilities. What you suggest is logical, however I think there is another important reaction that might be faster (I am not 100% sure). What reactions (other than aldol) do you know of aldehydes with hydroxide?

Hint: I'm thinking of a named reaction...

Incidentally, what is your friend's prediction?

[Steenrod]

The only other reaction I know is the Cannizarro one.He feels it will be Cannizaro.

[Dan]

Yes, an intramolecular Cannizzaro reaction can certainly occur to give sodium lactate. But as I say, I would expect quite a complex mixture in this reaction and I am not 100% sure what the major product is. Maybe someone else knows?

[Steenrod]

Why will there be Cannizaro?

[Dan]

Why not? You have a non-enolisable aldehyde present, and they have been well known to undergo Cannizzaro reactions for 150 years or so. Furthermore, the hydride shift is intramolecular so will be much faster than a bimolecular Cannizzaro (which are usually relatively slow compared to aldol reactions).

You also have an enolisable ketone group present, which could participate in an aldol reaction as you say.

Given the intramolecular nature of the Cannizzaro, I wouldn't be surprised if it is faster than aldol processes.

[Steenrod]

Thanks!I myself could not have thought of that.

[zhangcarlin]

i think you can get a tar if you do this reaction.