Molecular oxygen is one of the most attractive oxidants in organic synthesis because it is highly soluble in subcritical water. In this study, indane derivatives were oxidized to the corresponding isobenzofuran-1(3H)-one with molecular oxygen and isobenzofuran-1,3-dione with a mixture of molecular oxygen and H2O2 in subcritical water. This paper describes a simple, economic, environmentally benign,and general procedure that can be used for the synthesis of substituted isobenzofuran-1(3H)-ones and isobenzofuran-1,3-diones in only one step and without catalyst.