Reactions of Cyclohexanone with Metal Vapors

Article abstract of DOI:10.1021/jo00316a008

Metal atom vapors of several d and f transition elements were cocondensed with cyclohexanone at -196 deg C.Radical reduction of cyclohexanone to <1,1'-bicyclohexyl>-1,1'-diol, a pinacol, was observed for elements which are both highly electropositive and form strong metal-oxygen bonds, for example, the early transition, lanthanide, and actinide elements.High yields of aldol condensation products were produced along with a small amount of bicyclohexylidene.Metal atoms of the latter transition elements were much less reactive with cyclohexanone and did not yield a pinacol product.Titanium clusters were prepared by codepositing titanium atoms with a large excess of solvent.Titanium clusters were less reactive than titanium atoms toward cyclohexanone radical reduction reactions.High surface area titanium powders produced by solution techniques yield pinacols when cyclohexanone reacts in excess and further deoxygenate pinacolic dianions to olefins under conditions of limited stoichiometry.