CHEM 203 Lecture Notes - Lecture 13: Ozonide, Ozonolysis, Acetaldehyde
Document Summary
Absence of rearrangements during the addition of o3 to an alkene (= no cationic intermediates) Concerted reaction: one in which two or more bonds are formed / broken simultaneously, through an orderly movement of multiple electron pairs, leading to a product through a single chemical event (= without the intervention of reaction intermediates) Reaction of ozonides with metallic zinc (source of electrons) and acid: formation of aldehydes and / or ketones (no mechanism). H same products: ozonolysis does not distinguish between cis & trans alkene isomers. Reaction of ozonides with h2o2 and acid: formation of carboxylic acids and / or ketones (no mechanism): Agents containing metals in a high oxidation state: mno4. Analogy between the electronic distribution in the molecule of o3 and in that of oso4: Ability of oso4 to add to olefinic bonds through a concerted mechanism similar to a 1,3- dipolar cycloaddition: Driving force for the above reaction: reduction of os(viii) to os(vi):
