TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The educt (2a) and (3a) are prepared by: (x1) reacting 2,5-dimethyl furan with maleic anhydride by Diels-Alder cycloaddition to form 1,7-dimethyl-4,10-dioxa-tricyclo(5.2.1.0(2,6))dec-8-ene-3,5-dione (1a); (x2) dehydrating (1a) in the presence of an acid to form (2a); and, in case of preparing (3a), (x3) reduction of (2a) in the presence of a hydride reagent to form (3a). Preferred Definitions:    R1-R7 = 1-12C alkyl, fluoroalkyl or alkoxy, F, Cl or CN; and    Ar1 = 4-alkylphenyl or 2,4,6-trialkylphenyl.    EXAMPLE - A 1.6M n-butyl lithium solution in hexanes (120 ml) was added dropwise to a stirred solution of diisopropylamine (27 ml) in anhydrous petrol 40-60 (200 ml) at 0 degrees C under nitrogen. The lithium diisopropylamide solution was stirred at 0 degrees C for 30 minutes and then added dropwise to a stirred solution of 1-methoxy-4,7-dimethyl-1,3-dihydroisobenzofuran (17.04 g) in anhydrous petrol 40-60 (500 ml) at 0 degrees C under nitrogen. The reaction mixture was allowed to warm to 22 degrees C and stirred for 3 hours. Water (500 ml) was added to the reaction mixture and the organic layer was separated. The aqueous layer was reextracted with petrol 40-60 (200 ml). The combined extracts are washed with water (2x 200 ml) and dried. The solution of 4,7-dimethylisobenzofuran in petroleum ether 40-60 ( approximately 800 ml) was charged to a flask under nitrogen and a solution of p-benzoquinone in tetrahydrofuran (100 ml) was added dropwise at 22 degrees C. The reaction mixture was stirred for 17 hours. The solvents were removed. The solids were dissolved in a small volume of tetrahydrofuran and a large excess of petrol 40-60 was added. The crude product was filtered off, washed with petrol 40-60, dried and recrystallized to give 1,4,8,11-tetramethyl-5,14,7,12-diepoxy-5,7,12,14-octahydropentacene-6,13-dione (A1). (A1) (1.27 g), sodium acetate (0.13 g) and methanol (10 ml) were charged into a vial and heated at 160 degrees C for 5 minutes. The precipitate that formed was filtered off, washed with cold methanol, and dried to give 1,4,8,11-tetramethyl-6,13-pentacenequinone. A flask was charged with triethylsilylacetylene (6.1 ml) and anhydrous diethyl ether (100 ml) under nitrogen. The solution was cooled to 0 degrees C and a solution of 2.5M n-butyl lithium in hexanes (12.4 ml) was added dropwise. The reaction mixture was removed from the ice-bath and stirred for 1 hour at 22 degrees C. 1,4,8,11-Tetramethyl-6,13-pentacenequinone (1.13 g) was added and the reaction mixture was stirred at 22 degrees C for 2 hours. Anhydrous tetrahydrofuran (100 ml) was added and the reaction mixture was stirred for a further 18 hours. A saturated solution of stannous (II) chloride in 10% hydrochloric acid solution (20 ml) was added and the solution was stirred under nitrogen for 30 minutes. The reaction mixture was worked up to give 1,4,8,11-tetramethyl-6,13-bis(triethylsilylethynyl)pentacene (1.15 g, 61%).