# Effect of periodic acid on cyclohexane derivatives

Periodic acid (per-iodic acid, $\ce{HIO4}$ ) cleaves vicinal diols(to carbonyls) via a cyclic intermediate.

Due to the cyclic intermediate, it needs a syn configuration for the $\ce{-OH}$ groups for the reaction.

Exactly which configurations are allowed on cyclohexane derivatives?

Let's take 1,2-dihydroxycyclohexane(boat conformer). If the two hydroxy groups are both on the axial positions (trans- ), then obviously the reaction will not take place.

What about when the two are cis- (one axial, one equatorial), and when they are both equatorial (trans- )?

(My original question had to do with diastereomers of cyclic glucose--aldohexoses--but I realised that the extra hydroxy groups make the reaction more complicated)