In a previous paper? it was shown that d-xylal by means of ozone could be degraded to a tetrose, which was identified as d-threose. Ozone apparently had a dualistic action. Firstly, it was added to the double bond, forming an unstable ozonide, which in turn was broken down under the influence of the solvent, acetic acid, to two aldehyde groups. Secondly, cleavage of the 1, 5-oxygen ring took place, a fact which had to be assumed since a free tetrose and ...
