Asymmetric Reductions. Part I. Reduction of Ketones with Active lsobornyloxyaluminium Dichloride

'A series of acyclic ketones has been reduced with active isobornyloxyaluminium  dichloride, prepared from (-) isoborneol and mixed hydride to obtain partially active alcohols. The optical purity of the alcohol ranges from a minimum of 2.8% in case of methylethylcarbinol to a maximum. of 25.9% in case of methylphenylcarbinol. The preponderant enantiomer in each case has the absolute R-configuration, predictable from the preferred transition state of the reaction. The method is simple and may be useful for the preparation of partially active alcohols'.