MOST electrophilic
reactions of anthmcene take place at the meso-positions. For example, nitmtion gives 9-nitmanthmcene and then 9,1g-dinitroanthmcens (1). In addition, nitration of anthmrfuinone affords I-nitroanthmquinone. Consequently, prepamtions of 8-substituted onthmcenes require tedious routes and a majority of 8polysubstituted anthmcenes remain unknown. We wish to report the striking isomer distribution observed on the nitmtion of 9,10-dihydro-9,1O-ethanoanthmcene. This observation may suggest a geneml principle for the prepamtion of 8-substituted anthmcenes. Treatment of 9,1O-dihydm-9,lGethanoanthmcene (DEA) (I) (2) with one molar equivalent of nitric acid in acetic anhydride-nitrornethane solution at O-3' afforded a high yield (82%) of knitm-DEA (II), m.p. 164-l&?. The positions of the introduced nitro groups of this compound (II) and the polynitm compounds described below were *I Paper V, H. Tanida, T. Tsuji, and H. Ishitobi, J. Am. Chem. Sot., submitted to. l 2 All melting points were taken by capillary and am uncorrected. Satisfactory analyses were obtained for all compounds described. l 5 The a-polymorph is soluble in chloroform, but the B-polymorph is not. Identities of both crystals were determined by mixture melting point and comparison of the infmred spectm in dimethyl formamide. * * A resonance form which is analogous ta the valence-band of VII, although it is planar in this case, is often employed to explain the high reactivity of the B-positions of diphenylene. For example, see ref. 8.