The degradation pathways of gasoline oxygenates (MTBE, di-isopropyl ether (DIPE), ETBE, TAME) under ultrasonic irradiation were studied. The carbon centered radical 1 generated from a-hydrogen abstraction by OH radical reacted with oxygen at diffusion controlled rate constants generating peroxyl radicals. The formation of acetone from TBF was relatively minor and the rate of formation was slower than from MTBE when R″=H. Radical 16 carbonyl compound generated acetone when R=H by the reactions with •OH and following oxidation, and alcoholic compound generated a carboxylic acid and an acetate after oxidation reaction. The postulated pathways well explained the results from the product study in the degradation of gasoline oxygenates under ultrasonic irradiation. This is an abstract of a paper presented at the 223rd ACS National Meeting (Orlando, FL 4/7-11/2002).