Ketones, polycyclic Friedel-Crafts reaction

Friedel-Crafts Acylation, The Friedel-Crafts acylation procedure is the most important method for preparing aromatic ketones and their derivatives. Acetyl chloride (acetic anhydride) reacts with benzene in the presence of aluminum chloride or acid catalysts to produce acetophenone [98-86-2], CgHgO (1-phenylethanone). Benzene can also be condensed with dicarboxylic acid anhydrides to yield benzoyl derivatives of carboxylic acids. These benzoyl derivatives are often used for constructing polycyclic molecules (Haworth reaction). For example, benzene reacts with succinic anhydride in the presence of aluminum chloride to produce p-benzoylpropionic acid [2051-95-8] which is converted into a-tetralone [529-34-0] (30). 

Gore, P. H. The Friedel-Crafts acylation reaction and its application to polycyclic aromatic hydrocarbons. Chem. Rev. 1955, 55, 229-281. Eyiey, S. C., Rainey, D. K. Aldehydes and ketones. General and Synthetic Methods 1981,4, 26-86. 

Since the polycyclic ketones required for the Scholl reaction are generally prepared by the Friedel-Crafts synthesis, the two reactions can be combined thus, passing a stream of oxygen into an aluminum chloride-sodium chloride melt containing 1-benzoylpyrene and /7-toluoyl chloride yields 3-methyl-8,16-... 

As alluded (vide supra), some confusion may arise with respect to this named reaction as there is reference in the literature to an alternative reaction with the same name. The Bradsher reaction forms aromatic rings but via an acid-catalyzed Friedel-Crafts-like process. Thus diaryl-methanes having a carbonyl group in the ortho position can undergo a cyclodehydration reaction to generate the corresponding anthracene derivatives. In this respect, the Bradsher reaction is related to the Elbs reaction, which involves the pyrolytic cyclization of diaryl ketones 6 having an ortho methyl or methylene substituent for the formation of polycyclic aromatics 7. 

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