please explain the reaction of HIO4 in the chapter alcohol and ether.

1,2- or vicinal diols are cleaved by periodic acid, HIO4, into two carbonyl compounds.
The reaction is selective for 1,2-diols.
The reaction occurs via the formation of a cyclic periodate ester
This can be used as a functional group test for 1,2-diols.
The products are determined by the substituents on the diol.
The mechanism is not trivial, so attention here is focused on the actual cleavage step. Prior to this, the alcohol reacts to form a cyclic periodate ester . The periodate ester undergoes are arrangement of the electrons, cleaving the C-C bond, and forming two C=O.