NaNO2-mediated transformation of aliphatic secondary nitroalkanes into ketones or oximes under neutral, aqueous conditions: how the nitro derivative catalyzes its own transformation.

The nitrosation of secondary nitro derivatives into ketones or oximes depending on the nitro substituents has been reinvestigated. The reaction efficiently takes place under neutral conditions, thus allowing acid-sensitive substrates to be converted in very good yields. The generation of nitrosating species under such mild conditions is unprecedented. Mechanistic investigations strongly suggest that they result from the nucleophilic attack of the nitrite anion on the aci-nitro(nate) form of the secondary nitroalkane. The latter acts in turn as an autocatalyst for its own transformation by means of the nitrosating species generated in situ from it.