Ketones by the Nef reaction

A zinc-silver couple has been reported to be an improved reagent for the reductive addition of allylic bromides to nitriles. l-Trimethylsilyl-2-methyl-cyclopropane is a convenient regio- and stereospecific precursor of unsaturated ketones [equation (37)]. The reaction of allylsilanes with a-nitro-olefins has been found to proceed smoothly in the presence of aluminium trichloride [equation (38)]. The unstable nitronic acid product may be converted readily into the unsaturated ketone by the Nef reaction. 

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