Aromatic lithiation directed by the carboxylic acid group. Synthesis of 9-substituted dibenzodioxin-1-carboxylic acids and 6-substituted phenoxathiin-4-carboxylic acids

BD Palmer, M Boyd, WA Denny

Index: Palmer, Brian D.; Boyd, Maruta; Denny, William A. Journal of Organic Chemistry, 1990 , vol. 55, # 2 p. 438 - 441

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Citation Number: 24

Abstract

An efficient procedure has been developed for the regiospecific synthesis of 9-substituted dibenzo [1, 4] dioxin-1-carboxylic acid derivatives. Lithiation of dibenzo [1, 4] dioxin-l- carboxylic acid forms the lithium carboxylate, which directs subsequent metalation exclusively to the 9-position. Conditions for the controlled mono-and dilithiation of dibenzo [1, 4] dioxin itself, leading to the direct synthesis of the corresponding mono-and isomeric ...