Method for producing cyclopropyl-substituted acetophenones

A method for preparing a cyclopropyl-substituted acetophenone of formula (I),

• comprising
• a) in a first step reacting a benzylmagnesium halide or a benzylzinc halide (II) with a cyclopropyl alkyl ketone (III) to give an alcohol (IV),
• b) in a second step converting the alcohol (IV) to a halohydrin (V) by free-radical halogenation,
• c) in a third step converting the halohydrin (V) to an epoxide (VI) by addition of base,
• d) in a fourth step converting the epoxide (VI) to the cyclopropyl-substituted acetophenone (I) under thermal Lewis acid or Brønsted acid conditions,
• wherein
• R1 is chlorine, bromine, iodine, alkoxy, amino, cyano, nitro, C1-C4-alkyl or is unsubstituted phenyl or phenyl substituted by s radicals selected from the group consisting of chlorine, fluorine, methoxy and ethoxy,
• R2 is C1-C4-alkyl or is unsubstituted phenyl or phenyl substituted by s radicals selected from the group consisting of chlorine, fluorine, methoxy and ethoxy,
• s is 1, 2 or 3,
• X1, X2 are each independently chlorine, bromine or iodine.