Highly dispersed potassium on alumina as a metalating agent. Alkylation of enolizable compounds

Highly dispersed potassium on alumina (K/Al₂O₃) acts as a metalating agent towards enolizable compounds and the intermediate organopotassium derivatives can be alkylated with primary alkyl bromides. The reaction conditions are dependent on the substrate. In particular, tetrahydrofuran is the solvent of choice for the metalation of nitriles and aldehydeN,N-dimethylhydrazones at ?60°C and of N-cyclohexyl ketimines at room temperature, whereas hexane must be used for ketones.