91Ó°ÊÓ

Diols can be categorized into vicinal and germinal diols. The two hydroxyl groups are connected to the same carbon atom in germinal diols. Vicinal diols comprise two hydroxyl groups connected to adjacent atoms.

Glycols created by the dihydroxylation of alkenes are cleaved by the periodic acid (HIO₄). The products generated in this reaction are ketones and aldehydes.The structures of unknown sugars can be identified by periodic acid cleavage.

(a)1,2-diol get subjected to cleavage in the presence of HlO₄ to generate ketones and aldehydes. Butane-2,3-diol undergoes cleavage in the presence of HIO₄to generate two equivalents of acetaldehyde. The reaction can be given as:

Periodic acid cleavage of compound a

(b)1-(hydroxymethyl) cyclopentanol undergoes cleavage in the presence of HlO₄ to generate cyclopentanone and formaldehyde. The reaction can be given as:

Periodic acid cleavage of compound b

(c)2-phenylpentane-2,3-diol undergoes cleavage in the presence of HlO₄ to generate acetophenone and propionaldehyde. The reaction can be given as:

Periodic acid cleavage of compound c

(d)Bridged 1, 2-diol undergoes cleavage in the presence of HlO₄ to generate dialdehyde as the product. The reaction can be given as:

Periodic cleavage of compound d