Oxidative cleavage by reaction with ozone

The reaction of alkenes with ozone at low temperature produces an intermediate molozonide (or primary ozonide) which rapidly rearranges to form an ozonide. This leads to the cleavage of the C=C double bond. 

This is known as a 1,3-dipolar addition (ozone is a 1,3-dipole) 

The rearrangement leads to formation of two OO bonds at the expense of a C C bond and a very weak (H) bond 

The intermediate ozonide can then be reduced to aldehydes/ketones or be oxidised to carboxylic acids. 

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