Conversion of α, α′-dichlorodiazene dioxides using levulinic acid under solvent-free conditions to α-chloroketones through a three-step domino process

α-Chloroketones find numerous synthetic uses. We have developed a simple method of preparation of these compounds starting from alkenes adopting the Green Chemistry principle of solvent free reaction. The procedure involves addition of NOCl generated in situ by the reaction of AcOH-HCl (3 : 1) with amyl nitrite to alkenes and treating the α-chloronitroso compounds obtained as dimers with levulinic acid in presence of a few drops of 6N HCl, the latter being a three-step domino reaction, in which the first is dissociation of dimer to monomer, the second is tautomerisation of the nitroso function to oxime followed by deoximation in the third step. The yields are excellent. Since the starting compounds are readily available alkenes and the reaction is carried out under mild conditions leading to excellent yields of highly useful α-chloroketones, the procedure has the potential of wide application. © Indian Academy of Sciences