Synthesis and properties of acepleiadylene-5,6-dione and acepleiadylene-5,8-dione

Abstract

Acepleiadylene-5,8-dione (1) and acepleiadylene-5,6-dione (2) have been synthesized by the stepwise oxidation of 6,7-dihydrocyclohept[fg]acenaphthene-5,8-dione (4) and 7,8-dihydrocyclohept[fg]acenaphthene-5,6-dione (21) derived from compound (4), respectively. The reduction potentials of compounds (1) and (2) were determined by cyclic voltammetry which showed that E₁=–0.50 V and E₂=–0.84 V for the former, and E₁=E₂=–0.29 V for the latter. Spectral and electrochemical data suggest that both diones (1) and (2) are [14]annulenediones with a vinyl cross-link. 5,8- and 5,6-Dihydroxyacepleiadylene, (9′) and (22′), exist in their keto-forms, 6,7-dihydrocyclohept[fg]acenaphthylene-5,8-dione (9) and 7,8-dihydrocyclohept[fg]acenaphthylene-5,6-dione (22), respectively.