Synthesis of γ‐Keto Sulfones through a Three‐Component Reaction of Cyclopropanols, DABCO ⋅ (SO2)2 and Alkyl Halides.

A route to γ‐keto sulfones through a metal‐free reaction of cyclopropanols, DABCO ⋅ (SO2)2 and alkyl halides is described. This reaction occurs under mild conditions in the absence of any catalysts, additives, or oxidants. Various functional groups including as ester, amino, methoxy, bromo, trifluoromethyl, nitro and carbonyl are tolerated well in this transformation, and the corresponding γ‐keto sulfones are afforded in 35% to 95% yields. The proposed mechanism implies that this reaction proceeds through γ‐keto sulfinate intermediate generated in situ, which further undergoes nucleophilic substitution with alkyl halides leading to γ‐keto sulfones. [ABSTRACT FROM AUTHOR]