- Fluorinated cyclopropanecarboxylic acids and their derivatives
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The addition of halofluorocarbenes such as :CF2, :CClF or :CBrF, generated from the appropriate halofluoromethanes with bases, to butadiene or isoprene gives the corresponding l-vinyl substituted halofluorocyclopropanes in moderate to good yield. The vinyl group facilitates the carbene addition and permits a subsequent wide derivatisation. Several transformations including hydroboration, oxidation and Curtius degradation are presented. Furthermore, replacement of the chlorine atom in 2-chloro-2-fluorocyclopropanecarboxylic acid derivatives by hydrogen is achieved catalytically with Raney nickel. This sequence provides a convenient route to mono-fluorine substituted cyclopropane carboxylic acids.
- Gassen,Baasner
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p. 127 - 139
(2007/10/02)
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