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Partially Benzoanellated Centrohexaquinanes: Oxidative Degradation of Centropolyindanes by Using Ruthenium(VIII) Oxide and Ozone
Author(s) -
Gestmann Detlef,
Kuck Dietmar,
Pritzkow Hans
Publication year - 1996
Publication title -
liebigs annalen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0947-3440
DOI - 10.1002/jlac.199619960903
Subject(s) - chemistry , ruthenium , chromophore , ozonolysis , ozone , stoichiometry , oxide , photochemistry , degradation (telecommunications) , pyridine , oxidative phosphorylation , medicinal chemistry , organic chemistry , catalysis , telecommunications , biochemistry , computer science
The oxidative degradation of benzo nuclei of various higher contropolyindanes with ruthenium (VIII) oxide or ozone was studied to further explore the chemistry of partially benzoanellated centrohexaquinanes. Besides the two tribenzotri‐quinacenes 12 and 15 which were used as model substrates for oxidation with Ru VIII , centrohexaindane 1 was converted to the corresponding centrohexacyclic diketone 19 by using either RuO 4 in stoichiometric amounts or O 3 in dichloro‐methane/pyridine. Subsequent Wolff‐Kishner reduction of 19 gave pentabenzohexaquinane 4 . Correspondingly, tribenzocentrohexaquinane 2 was degraded by sequential ozonolysis/reduction to the C 2 v ‐symmetrical dibenzocentrohexaquinane 10 and monobenzocentrohexaquinane 11 in low yields (8–9% in each sequence). Due to the low efficiency of the ozonolyses, the parent centrohexaquinane 3 has remained elusive, yet. The deeply red centrohexacyclic 1,2‐diketone 19 was subjected to single‐crystal X‐ray structural analysis and found to bear an almost perfectly syn ‐coplanar α‐dicarbonyl chromophore with a strong and extremely low‐energy UV/Vis absorption (λ max = 512 and 531 nm).