Substitution of both chloro and sulfinyl groups of aryl 1-chlorocyclopropyl sulfoxides in one-pot via cyclopropylmagnesium carbenoids: a synthesis of multi-substituted cyclopropanes
The rearrangement of cyclopropylmagnesium carbenoids, which were generated from aryl 1-chlorocyclopropyl sulfoxides with a Grignard reagent, to allenes was found to be suppressed by adding HMPA as an additive. Alkylation of the cyclopropylmagnesium carbenoids with the Grignard reagent gives mainly alkylated cyclopropylmagnesium chloride instead. The cyclopropylmagnesium chloride intermediate can be