Sodium fluoride, reaction with chloro acids

Dihalocycloproparenes, in particular the chloro derivatives, are extremely susceptible to hydrolysis and react via ring opening to give carboxylic acid derivatives. Typically, 1,1-dichloro-2,5-diphenylbenzocyclopropene was converted to trimethyl 2,5-diphenylorthobenzoate (12a, 94%) upon reaction with sodium methoxide in benzene and workup in the presence of base. Methanolysis in the absence of base afforded methyl 2,5-diphenylbenzoate. " The same behavior applies to 1,1-dichloro- or l,l-dibromo-2,7-diphenylcyclopropa[()]naphthalene. 1,1-Difluorobenzocyclopropene was hydrolyzed with water to benzoic acid, and the intermediate benzoyl fluoride was isolated and characterized. The hydrolysis of l,l-dihalocyclopropa[6]-naphthalenes afforded naphthalene-2-carboxylic acid, while acid-catalyzed methanolysis of... 

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