TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The inorganic compound solid material is a metal oxide, preferably fine particles of metal oxide. The metal oxide is titanium dioxide, aluminum oxide, silicon dioxide, zirconium oxide or zinc oxide.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The step (B) comprises: obtaining substituted compounds of formula (IV) using (II); and obtaining (I) using (IV). SPECIFIC COMPOUNDS - The preparation of 17 compounds (I) is disclosed e.g. 4-ethoxy-1,2-dihydroxy-anthraquinone of formula (Ia), 4-butoxy-1,2-dihydroxy-anthraquinone, 1,2-dihydroxy-4-octyloxy-anthraquinone, 4,4'-(butane-1,4-diylbis(oxy))bis(1,2-dihydroxyanthracene-9,10-dione) and 4,4'-(hexane-1,6-diylbis(oxy))bis(1,2-dihydroxyanthracene-9,10-dione).    EXAMPLE - Purpurin (100 g) was dissolved in N,N'-dimethylacetamide (600 ml) followed by addition of potassium carbonate (108 g). Then alpha , alpha -dichlorodiphenyl methane (111 g) was added dropwise to the reaction mixture and reacted at 80 degrees C for 9 hours. The reaction liquid was transferred to a mixed solvent of water (1 l) and methanol (1 l). The reaction solution was stirred, cooled and then filtered. The obtained crude crystals were washed with water (1 l) and methanol (1 l), and dried at 50 degrees C to obtain 5-hydroxy-2,2-diphenyl-1,3-dioxa-cyclopenta(a)anthracene-6,11-dione. Aqueous potassium hydroxide solution (50%, 4.4 g), tetrabutylammonium bromide (11.6 g), water (15 ml) and toluene (30 ml) were added to 5-hydroxy-2,2-diphenyl-1,3-dioxa-cyclopenta(a)anthracene-6,11-dione (12.6 g), and then ethyl iodide (7.5 g) was added dropwise. The reaction mixture was heated and refluxing at 65 degrees C for 6 hours, and then cooled. The precipitated crystals were washed and purified to obtain 5-ethoxy-2,2-diphenyl-1,3-dioxa-cyclopenta(a)anthracene-6,11-dione. Then 5-ethoxy-2,2-diphenyl-1,3-dioxa-cyclopenta(a)anthracene-6,11-dione (150 g) was dissolved in sulfuric acid (150 g) and heated at 60 degrees C for 1 hour. The reaction liquid was slowly transferred to ice-cooled methanol (1.5 l). The obtained crystals were filtered, and washed with water (1 l) and methanol (1 l) to obtain 4-ethoxy-1,2-dihydroxy-anthraquinone (97.9% purity).