A number of polyfiuoro-1-methyieneindanes have been obtained by copyrolysis of 1,1-dichloropolyfluoroindanes with CF2= CF2, CHClF2, CHCl2F and CHCl3. A possibility is shown for the reaction of 1,1-dichloroctafluoroindan with CHClF2 to proceed by way of difluorocarbene insertion into the CCl bond of the benzylic position of This indan, with subsequent dechlorination of the insertion product.