Ozonides derived from mono-substituted alkenes react with methyl (triphenylphosphorany1idene)acetate or (triphenylphosphorany1idene)acetophenone to form trans-cu,p-unsaturated esters or ketones, respectively, in high yields. ... Ozonolysis is an important tool for the cleavage of carbon- carbon double bonds.' The intermediate ozonides can be reduced in situ to give the corresponding carbonyl compounds or alcohols by treating them with ...