In the presence of potassium carbonate or potash, acetone forms an addition product with 2∶6-dimethoxy quinone. Its properties and reactions are described. They give evidence for the presence of an aliphatic hydroxyl group and a ketone carbonyl. The combination is considered to involve addition of the acetone molecule at the C=O group in the 4-position of the quinone. Methyl ethyl ketone also forms a similar addition compound. Other simplep-benzoquinones do not give this type of compounds.