Aspects of catalysis. Part V. Stereoselectivity in the transition metal-catalysed transfer of hydrogen to cyclohexanones

Abstract

Substituted cyclohexanones (3- and 4-t-butyl, 2-methyl, and 3,3,5-trimethyl) are reduced to alcohols when heated with propan-2-ol in the presence of metal catalysts prepared by precipitation methods; ruthenium is particularly effective. The stereoselectivity of the reduction depends on the metal used, and on kinetic and equilibrium control during the reaction.