[534-07-6] · C3H4Cl2O · 1,3-Dichloroacetone · (MW 126.97)
Alternate Name: 1,3-dichloro-2-propanone.
Physical Data: mp 39-41 °C; bp 173 °C; d 1.383 g cm-3.
Solubility: sol organic solvents.
Form Supplied in: solid; commercially available.
Handling, Storage, and Precautions: highly corrosive and toxic. Use in a fume hood.
The reagent is useful as starting material for a simple one-pot synthesis of many 1-arylcyclopropanols (eq 1).4,5 In this procedure the initially formed 1,3-dichloro-2-aryl isopropoxide is reduced to the 1-aryl cyclopropoxide by low-valent iron, generated in situ by the reaction of Ethylmagnesium Bromide with Iron(III) Chloride.6 The general method can be extended to the synthesis of 1-alkylcyclopropanols by using an excess of Lithium powder as the reducing agent in place of the EtMgBr/FeCl3.7 A somewhat related synthesis of 1-alkyl- or 1-arylcyclopropanols makes use of the reaction of ethyl 3-bromopropionate with 1 equiv of Grignard reagent in the presence of 2 equiv of Samarium(II) Iodide.8
1,3-Dichloroacetone also serves as the starting reagent in a general synthesis of cyclopropenones and their acetals (eq 2).3 The initially formed cyclopropenone acetal (1) can be alkylated a second time if desired, and then hydrolyzed to a dialkylcyclopropenone.
Charles H. DePuy
University of Colorado, Boulder, CO, USA