Ozonolysis of Enol Ethers, Part 101: A Mechanistic Study of the Regioselectivity of Ozone Oxygen Distribution During Ozonolysis of Exocyclic 2-Alkoxy- alkylidene 1-Mono- and 1,3-Dicarbonyl Compounds

Enol Ethers bearing one or two ester carbonyl groups as acceptor substituent(s) at b-carbon yield ozonides during ozonations in inert solvents whereas those bearing one or two ketone carbonyl groups suffer Baeyer-Villiger related rearrangements with formation of carboxylic acid derivatives. It is assumed that in both cases enol ether C,C double bonds are cleaved in a way that ether substituted a-carbon accepts one ozone oxygen and acceptor substituted b-carbon accepts two ozone oxygens. An alternative mechanistic proposal attempts to avoid permanent contradictory statements on the regioselectivety of peroxidised olefinic enol ether carbons.