A five fused ring non-benzenoid quinone containing a seven-membered ring: synthesis and properties of cyclohept[f,g]aceanthrylene-5,8-dione and 1,2-dihydrocyclohept[f,g]aceanthrylene-5,8-dione

Abstract

Cyclohept[f,g]aceanthrylene-5,8-dione 16 and 1,2-dihydrocyclohept[f,g]aceanthrylene-5,8-dione 15 have both been synthesized in four steps from aceanthrene 9 in 8 and 7% overall yield, respectively. On the basis of their reduction potentials, the compound 16 was shown to be an [18]annulenedione with a higher reduction potential than the isomeric cyclopenta[c,d]pleiadene-5,10-dione 2. An unsuccessful attempt to synthesize cyclohept[f,g]aceanthrylene 21 as well as the efficient synthesis of aceanthrene 9 from anthracene is also described.