Non-benzenoid aromatic compounds

Compounds of special interest whose preparation is described include 1,2,3-benzothiadiazole 1,1-dioxide (a benzyne precursor under exceptionally mild conditions), bis(l,3-diphenylimida-zolidinylidene-2) (whose chemistry is quite remarkable), 6- di-melhylamino)julvene (a useful intermediate for fused-ring non-benzenoid aromatic compounds), dipkenylcyclopropenone (the synthesis of which is a milestone in theoretical organic chemistry), ketene di(2-melhoxyethyl) acetal (the easiest ketene acetal to prepare), 2-methylcyclopenlane-l,3-dione (a useful intermediate in steroid synthesis), and 2-phenyl-5-oxazolone (an important intermediate in amino acid chemistry). 

Non-benzenoid aromatic compounds containing a hydroxy group also react with arenediazonium ions and form arylazo derivatives. The first case of such an azo coupling process was found by Nozoe (1949) in his classic work on the natural product hinokitiol (12.15, R=CH3 Nozoe, 1959, 1991). Shortly afterwards Nozoe et al. 

On the other hand, the anodic oxidation of 1,3,5-cycloheptatrienes is one of the most powerful key tools for the preparation of a variety of non-benzenoid aromatic compounds such as tropylium salts, tropones, tropolones, 2H -cyclohcpta h furan-2-oncs and azulenes14. 

Untch, K. First International Symposium on the Chemistry of Non-benzenoid Aromatic Compounds, Sendai, Japan, August, 1970. See also Jones, W.M. Angew. Chem. Int. Ed. Engl. 1972, 11, 325. 

Non-benzenoid aromatic compounds, flash vacuum pyrolysis for, 21 148 Non-benzenoid quinones, 21 238 Nonbenzidine-based dyes, 9 448 Nonblack fillers, 21 781... 

Non-Benzenoid Aromatic Compounds.—The synthesis of aromatic molecules containing small, medium, and large rings, using the reaction of dicarbonyl compounds and bis-ylides, has been thoroughly reviewed.95... 

R. A. Raphael, in Non-Benzenoid Aromatic Compounds (Ed. D. Ginsburg), Chapter VIII, Interscience Publishers, New York, 1958. 

T. Nozoe, in Non-Benzenoid Aromatic Compounds (D. Gins-burg, ed.) p. 339. Wiley (Interscience), New York and London, 1959. 

J. P. Collman, L. S. Hegedus, J. R. Norton and R. G. Finke, Principles and Applications of Organotransition Metal Chemistry, University Science Books, Mill Valley, California, 1987 P. L. Pauson, in Non-Benzenoid Aromatic Compounds (Ed. D. Ginsburg), Interscience Publishers, New York, 1959. 

D. Lloyd, Carbocyclic Non-Benzenoid Aromatic Compounds, p. 98. Elsevier, Amsterdam, 1966. 

Nozoe T (1959) In Ginsburg D (ed) Non-benzenoid Aromatic Compounds. Intere-science Publishers Inc., New York, pp 339-463... 

Many aromatic compounds have considerable resonance stabilization but do not possess a benzene nucleus, or in the case of a fused polycyclic system, the molecular skeleton contains at least one ring that is not a benzene ring. The cyclopentadienyl anion C5HJ, the cycloheptatrienyl cation C7H+, the aromatic annulenes (except for [6]annulene, which is benzene), azulene, biphenylene and acenaphthylene (see Fig. 14.2.2(b)) are common examples of non-benzenoid aromatic hydrocarbons. The cyclic oxocarbon dianions C Of (n = 3,4,5,6) constitute a class of non-benzenoid aromatic compounds stabilized by two delocalized n electrons. Further details are given in Section 20.4.4. 

Ginsberg D (1959) Non-benzenoid aromatic compounds, Interscienoe Publishers, Inc New York, NY... 

Loyd D (1966) Carbocyclic Non-benzenoid aromatic compounds, Elsevier Publishing... 

MI1 D. Ginsburg (ed.), "Non-Benzenoid Aromatic Compounds" Inter-... 

MI1 D. M. G. Lloyd, "Carbocyclic Non-Benzenoid Aromatic Compounds",... 

Cf, for example Craig, D. P. Non-Benzenoid Aromatic Compounds (D. Ginsburg, ed.), p. 1. New York Interscience Publishers 1959. 

Non-benzenoid Aromatic Compounds.—The slow addition of lithium ethoxide in ethanol to a solution of reagents in DMF at —40 °C gave a small yield of the bicyclophane (85). ... 

Nozoe, T., in Non-Benzenoid Aromatic Compounds, Edited by Ginsburg, D., Interscience, New York, 1959, Chapter VIL... 

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