Oxygen oxidizes aromatic hydrocarbons in aq. acetone solns. containing ascorbic acid. Anthracene is oxidized to 9:10-anthra-quinone and 3:4-benzpyrene yields a mixture of 3:4-benz-pyrene-5:8-quinone and 3:4-benzpyrene-5:10-quinone. The oxidizing agent appears to be one of the products formed during autoxidation of ascorbic acid and is possibly de-hydroascorbic acid or a peroxide thereof. The mechanism seems to be similar to that which occurs during the inhibition of the autoxidation of aldehydes by aromatic hydrocarbons.