Organic Chem- Mechanism Question(Oxidation of Glycol)

[HclGuy]

Homework Statement

Write a detailed mechanism for the following reaction:
Attached picture

Homework Equations

N/A

The Attempt at a Solution

Okay, I know this is PART of the mechanism for the oxidation of a glycol by periodic acid which causes cleavage of the C-C bond between the glycol and forms 2 carbonyl groups. The thing is the cyclic periodate that is formed is only an intermediate , and I need to figure out a mechanism for that 1 Step. I have tried thinking about turning one of the -OH groups on the glycol into H2O to start a SN reaction, but it doesn't seem to work out. What I think I do know is that the oxidation state of the iodine atom is preserved in the cyclic periodate and that the periodic acid is the molecule that wants electrons. Other than that, I don't have a clue about how the mechanism works to form the cyclic periodate.

 

[chemisttree]

If you were to label the oxygens (O-18) of the glycol, would the intermediate contain both? If so, the H2O produced comes from periodic acid. From there, the mechanism is fairly straightforward... attach things that have electron density to things that don't. Intermediates that are positively charged and contain a proton, likely lose the proton to the solvent. The solvated protons can reprotonate elsewhere on the intermediate.

 

[HclGuy]

Thanks for the tip !, haven't thought about the oxygens from the glycol being the one on the cyclic periodate, was so obsessed with trying to turn one of the alcohols on the glycol into a leaving group and not the alcohol on the periodic acid.