Fries rearrangement alkaline

Only para coupling was observed during the alkaline ferricyanide oxidation of 4-hydroxy-3-(3-hydroxybenzoyl)benzoic acid. 7-Hydroxy-9-oxoxanthene-2-carboxylic acid (515) was obtained in 21% overall yield from methyl 4-hydroxybenzoate (78JCS(P1)876). The synthesis utilizes a photochemical Fries rearrangement of methyl 4-(3-methoxybenzoyloxy)benzoate to prepare the benzophenone (514 Scheme 189). A similar route was used to prepare 2-hydroxy-2 -methoxybenzophenones, which undergo intramolecular cyclization with loss of methanol on treatment with base. 

Friedel-Crafts reactions, 20, i, 29 Fries rearrangement, 21, 23 Froth dissipation, 20, 3 Fusiaryl chloride, 20, 29, 51 z-Furanacrylic acid, 20, 55 Furfural, 20, 35 Fdrylacrylic acid, 20, 55 Fusion, alkaline, of an aryl sulfonate, 21,... 

Dioxopentyl)-2-hydroxychromanones, such as (284), have been cyclo-dehydrated in high yield, under alkaline conditions, to the xanthone (285) this route resembles biosynthetic pathways.In a synthesis of benzoxanthones, a photo-induced Fries rearrangement of a 2-benzoyloxy-4-methoxy-6-methylben-zoyl ester was employed, but in several experiments a mixture of ketones was obtained. However, when the diester (286) was similarly treated, it gave the ketone (287), which cyclized to the xanthone (288). ... 

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