Ketones intramolecular Friedel-Crafts reaction

Intramolecular Friedel-Crafts reaction Worthy of mention is the case of intramolecular Friedel-Crafts-type reaction affording 4(lH)-quinolone derivatives [443]. Thus, after extensive investigations, the authors prepared a solid-supported Meldrum s acid derivative by alkylation of a Merrifield resin with ethyl acetoacetate, decarboxylation, and subsequent ketalization of the resulting supported ketone with malonic acid (638). Treatment with triethyl orthoformate and various arylamines (639) afforded immobilized arylamino-methylene derivatives of Meldrum s acid (640). Upon thermal cyclization, these intermediates afforded 4(lH)-quinolone derivatives with simultaneous release from the resin (641). Highly pure final compounds were obtained in moderate to good yields. The resin was recovered in the form of the precursor of (638), i.e., the ketone (642), and thus could be potentially reused (Scheme 133). 

Several cycloheptane derivatives have been prepared using intramolecular Friedel-Crafts reactions including the tetracyclic ketone (26) and double dibenzotropones , e.g. Acid-catalysed cyclizations of (o-(l-indanyl)-carboxylic acids (28 n = 3... 

Intramolecular Reactions.—Cyclo-oct-4-en-l-yl acetyl chloride gave a mixture of tricyclic ketones (190) and (191) when heated, preferably in the presence of triethyl-amine, via a keten intermediate, whereas on heating in the presence of tin tetrachloride, endo-2-chlorobicyclo[4,2,2]decan-8-one was obtained via an intramolecular Friedel-Crafts reaction. ... 

Iron salts have recently attracted considerable attention as inexpensive and environmentally friendly agents in a wide range of selective processes in organic synthesis. Over the past decade, FeCls 6H2O has shown to be an effective catalyst in the formation of carbon-carbon or carbon-nitrogen bonds, in intramolecular Friedel-Craft reactions and in the reduction of ketones or allylic alcohols. ... 

Each of the compounds indicated undergoes an intramolecular Friedel-Crafts acylation reaction to yield a cyclic ketone. Write the structure of the expected product in each case. 

Treatment of saturated azlactones with aromatic compounds under Friedel-Crafts conditions gives acylamino ketones in high yield (equation 46). 4-Benzyl-2-methyl-5(4H)-oxazolone undergoes an intramolecular reaction to yield an acetamidoindanone (equation 47). Friedel-Crafts reactions of 4-(arylmethylene)-5(4H)-oxazolones are complicated by the presence of an additional electrophilic centre (cf. 201) and may follow three courses. The unsaturated azlactone (189) adds benzene under the influence of aluminum chloride to form the saturated azlactone (207) in inert solvents (189) undergoes an intramolecular acylation to yield a mixture of the indenone (208) and the isoquinoline (209 Scheme 20). 

Based on the benzyl derivative (26), the first stable carborane-containing simple enol (27) was synthesized2 (Scheme 8). The acid chloride (28) readily enters into a Friedel-Crafts reaction with mesitylene to give ketone (29). Under the action of BuLi on a benzene-ether solution of ketone (29) enolate (30) is formed. Treatment of the latter with diluted HC1 solution results in enol (27). Starting from the benzyl derivative (31), carboranyl-substituted indene (32) was synthesized by intramolecular cyclization with a formation of ketone (33), whose reduction (34) followed by dehydration results in (32) (Scheme 9). 

Preparation of Carboxylic Acid Chlorides (and Anhydrides). Oxalyl chloride has found general application for the preparation of carboxylic acid chlorides since the reagent was introduced by Adams and Ulich. Acid chlorides produced by this means have subsequently featured in the synthesis of acyl azides, bromoalkenes, carboxamides, cinnolines, diazo ketones, (thio)esters, lactones, ketenes for cycloaddition reactions, intramolecular Friedel-Crafts acylation reactions, and the synthesis of pyridyl thioethers. ... 

The Friedel-Crafts alkylation is one of the oldest synthetic methodologies known. The catalytic asymmetric version of the reaction [311] enables the preparation of important chiral building blocks. Electron-rich aromatic and heteroaromatic compounds have been productively used in organocatalyzed enantioselective inter- and intramolecular Friedel-Craft-[312] type conjugate additions over different Michael acceptors such as, a,p-unsaturated aldehydes, a,P-unsaturated ketones, nitroole-fins, and a,p-unsaturated acyl phosphonates. 

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