An efficient route to aliphatic 2, 2-dichloroaldehydes via chlorination of aldehydes or alcohols with the system Cl2/quaternary ammonium chloride

F Bellesia, L De Buyck, F Ghelfi, UM Pagnoni…

Index: Bellesia, Franco; De Buyck, Laurent; Ghelfi, Franco; Pagnoni, Ugo M.; Parsons, Andrew F.; Pinetti, Adriano Synthesis, 2003 , # 14 p. 2173 - 2178

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Citation Number: 9

Abstract

The α-dichlorination of aldehydes needs two successive enolization steps and for a successful transformation the reaction has to be performed under acid-catalysis. In fact, in an alkaline medium, the halogenation would result in oxidation and aldol condensation. [16b] After the introduction of the first Cl-function, acid-catalysis, owing to the strongly reduced basicity of the carbonyl group, is unable to promote a sufficiently rapid second chlorination step and, as a ...