ò-Isophorone is an organic compound with the formula (CH<sub>3</sub>)<sub>3</sub>C<sub>6</sub>H<sub>7</sub>O. Classified as a ò,ó-unsaturated ketone, it is an isomer of and common impurity in the major industrial intermediate ñ-isophorone, which is produced from acetone. Like the alpha isomer, beta-isophorone is a colorless liquid.