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Abstract

3-Chlorononafluoro-1,5-hexadiene (I) is isomerized into 6-chlorononafluoro-1,4-hexadiene (II) by action of basic catalysts as sodium cyanide in anhydrous dimethylformamide, lithium chloride in dimethylformamide, and triethylamine in dioxane or dimethylformamide. Sodium cyanide also catalyzes addition of methanol to the chlorodiene I. The reaction course is more complex than in the alkoxide-catalyzed addition of primary alkohols to I. 6-Methoxynonafluoro-1,4-hexadiene (III), methyl perfluoro-3,6-heptadienoate (VII), and 3,6-dimethoxy-1,1,2,3,4,4,5,6,6-nonafluoro-1-hexene (VIII) have been isolated besides the known products 1,6-dimethoxy-1,1,2,3,4,5,6,6-octafluoro-2,4-hexadiene (IV) and 1,6-dimethoxy-1,1,2,3,4,4,5,6,6-nonafluoro-2-hexene (V). The hexene VIII reacts with sodium methoxide in methanol to give the diether V and with lithium chloride in dimethylformamide it gives 1-chloro-6-methoxy-1,1,2,3,4,4,5,6,6-nonafluoro-2-hexene (IX). Stereospecificity and mechanism of the reaction are discussed.